Cationic antiseptic compositions and methods of use

ABSTRACT

Antimicrobial compositions, especially those useful when applied topically, particularly to mucosal tissues (i.e., mucous membranes), including a cationic antiseptic such as biguanides and bisbiguanides such as chlorhexidine and its various salts including but not limited to the digluconate, diacetate, dimethosulfate, and dilactate salts; polymeric quaternary ammonium compounds such as polyhexamethylenebiguanide; silver and various silver complexes; small molecule quaternary ammonium compounds such as benzalkoium chloride and alkyl substituted derivatives; di-long chain alkyl (C8-C18) quaternary ammonium compounds; cetylpyridinium halides and their derivatives; benzethonium chloride and its alkyl substituted derivatives; and octenidine. The compositions can also include an enhancer component, a surfactant, a hydrophobic component, and/or a hydrophilic component. Such compositions provide effective topical antimicrobial activity and are accordingly useful in the treatment and/or prevention of conditions that are caused, or aggravated by, microorganisms (including viruses).

BACKGROUND

The use of antimicrobial agents plays an important part in currentmedical therapy. This is particularly true in the fields of dermatologyas well as skin and wound antisepsis, where the most effective course oftreatment for skin or mucous membranes, which are afflicted withbacterial, fungal, or viral infections or lesions, frequently includesthe use of a topical antimicrobial agent, such as antibiotics. Fordecades medicine has relied primarily upon antibiotics to fight systemicas well as topical infections.

Antibiotics are organic molecules produced by microorganisms that havethe capacity in dilute solutions (e.g., solutions less than 10 μg/ml andoften less than 1 μg/ml) to destroy or inhibit the growth of bacteriaand other microorganisms. They are generally effective at very lowlevels and are often safe with very few, if any, side effects.Antibiotics are commonly of a narrow spectrum of antimicrobial activity.Furthermore, they often act on very specific sites in cell membranes oron very specific metabolic pathways. This can tend to make it relativelyeasy for bacteria to develop resistance to the antibiotic(s) (i.e., thegenetically acquired ability to tolerate much higher concentrations ofantibiotic) either through natural selection, transmission of plasmidsencoding resistance, mutation, or by other means. Not only doesresistance eliminate the ability of a medication to treat an affliction,but it can also put the patient at further risk, especially if theantibiotic is one that is routinely used systemically.

In the past few decades it as been quite well established thatcolonization of the anterior nares with Staphylococcus aureus (SA) canlead to multiple problems. Medicine has relied primarily uponantibiotics for nasal decolonization. For example, bacitracin, neomycinsulfate, polymyxin B sulfate, gentamicin, framycetin-gramicidin,lysostaphin, methicillin, rifampin, tobramycin, nystatin, mupirocin, andcombinations thereof, have been used with varying success for nasaldecolonization.

For example, nasal colonization with SA in presurgical patients hasresulted in higher infection rates and higher rates of other nosocomialinfections such as catheter infections. Nasal colonization with SA inhemodialysis patients has resulted in a much higher incidence of bloodstream infections. Furthermore, it has been well established that theanterior nares is the ecological niche for SA colonization and thusspread of methicillin resistant staphylococcus aureus (MRSA) in ahospital or other health care facilities in the event of an outbreak canbe mitigated by decolonizing the anterior nares of patients andhealthcare workers.

Mupirocin, marketed as the calcium salt in Bactroban Nasal by GlaxoSmith Kline, is the only antibiotic approved by the Food and DrugAdministration for nasal decolonization use in the United States. Forexample, there are multiple reports of resistance to mupirocin when usedas a nasal decolonizing agent. Resistance rates have been reported ashigh as 25% and even as high as 50% (see, for example, E. Perez-Roth etal., Diag. Micro. Infect. Dis., 43:123-128 (2002) and H. Watanabe etal., J. Clin. Micro., 39(10): 3775-3777 (2001)). Even though presurgicaldecolonization of the anterior nares using mupirocin has been shown todecrease the risk of surgical site infection by as much as 2 to 10 times(T. Perl et al., Ann. Pharmacother., 32:S7-S16 (1998)), the highresistance rates to this antibiotic make it unsuitable for routine use.

Antiseptics, on the other hand, are synthetic molecules that destroy orinhibit microorganisms and virus by inhibiting metabolic pathways oraltering the cell envelope or both. They tend to have broader spectrumof antimicrobial activity and often act by nonspecific means such asdisruption of cell membranes, oxidation of cellular components,denaturation of proteins, etc. This nonspecific activity makes itdifficult for microorganisms to develop clinical resistance toantiseptics. For example, there are very few reports of clinicalresistance to antiseptics such as iodine, lower alcohols (ethanol,propanol, etc.), chlorhexidine, quaternary amine surfactants,chlorinated phenols, and the like. Some of these compounds, however,need to be used at concentrations that often result in irritation ortissue damage, especially if applied repeatedly. Furthermore, unlikeantibiotics, many antiseptics are not active in the presence of highlevels of organic compounds. For example, formulations containing iodineor quaternary ammonium compounds have been reported to be inactivated bythe presence of organic matter such as that in nasal or vaginalsecretions, and perhaps even on skin.

Many antiseptic compounds are viewed as irritants. For example,compositions containing iodine and/or chlorhexidine have been reportedto cause skin and mucosal tissue irritation. This is particularly truefor sensitive mucosal tissues, such as the anterior nares, nasal andesophageal cavities, which can have a high level of microbialcolonization in certain otherwise healthy individuals, as well asindividuals with infectious diseases such as chronic sinusitis.Additionally, due to the irritating nature many of these compounds maybe unsuitable for application to irritated or infected dermal tissue totreat skin conditions, such as lesions from impetigo and shingles.

Also, for certain applications, especially in the nose and mouth, it isparticularly desirable for the compositions to have little or no color,little or no odor, and an acceptable taste. Many antiseptics haveundesirable characteristics, such as iodine and iodophors, which have anorange to brown color and a definite odor at concentrations typicallyemployed for antisepsis.

Chlorhexidine gluconate (in combination with neomycin sulfate) has beensuggested for use in nasal decolonization with limited success. Forexample, Naseptin is an antibiotic emulsified cream comprising neomycinsulphate (3250 units/g) and chlorhexidine gluconate (0.1 wt-%) that incombination destroys bacteria. The product also contains arachis oil,cetostearyl alcohol/ethylene oxide concentrate, cetostearyl alcohol in awater base. The product must be used 4 times/day over 10 days toeradicate nasal carriage of staphylococci. In addition, U.S. Pat. No.6,214,866 discloses the use of chlorhexidine in combination with theantibiotic mupirocin.

Povidone-iodine has also been suggested for use in nasal decolonization(R. L. Hill and M. W. Casewell, Journal of Hospital Infection, 2000,Vol. 45, 198-205). Betadine Cream (5 wt-% povidone iodine) has beenfound to kill methicillin resistant staphylococcus aureus in vitro in anenrichment culture technique. Addition of nasal secretions decreased theactivity of the povidone-iodine by 80-90% by reaction of the free iodinewith the organic load. Other drawbacks of 5% povidone-iodine for use inpatients included: 1) a very dark brown color, 2) a low pH which cancause irritation, 3) a strong iodine odor.

The formulation of components can affect the performance and potentialirritation of antimicrobial agents. For example, many conventionalantimicrobial compositions are too low in viscosity and/or toohydrophilic in nature to maintain sufficient substantivity andpersistence to provide sufficient antimicrobial activity on moisttissue, such as the anterior nares or open, exuding, or infectedlesions. It has been reported that the presence of solvents can diminishthe antimicrobial activity of many antiseptics. Furthermore, it has beenreported that many surfactants can reduce the efficacy of antiseptics bysequestering the antiseptic in micelles. (H. B. Kostenbauer, Chapter 44in Disinfection, Sterilization, and Preservation, First addition, 1968,C. A. Lawrence and S. S. Block). Additionally, surfactants are oftenimplicated in contributing to irritation.

Thus, there is still a need for effective antimicrobial compositionsthat develop little resistance and are well-tolerated when used onmammalian tissue and especially on moist mammalian tissue such as in thenasal passages, anterior nares, vagina, and wounds.

SUMMARY OF THE INVENTION

The present invention provides antimicrobial compositions and methods ofusing and making the compositions. Such compositions are typicallyuseful when applied topically, particularly to mucosal tissues (i.e.,mucous membranes), although a wide variety of surfaces can be treated.They can provide effective reduction, prevention, or elimination ofmicrobes, particularly bacteria, fungi, and viruses. Preferably, themicrobes are of a relatively wide variety such that the compositions ofthe present invention have a broad spectrum of activity.

Compositions of the present invention provide effective topicalantimicrobial activity and are accordingly useful in the local treatmentand/or prevention of conditions that are caused, or aggravated by,microorganisms (including viruses, bacteria, fungi, mycoplasma, andprotozoa) on skin, wounds, and/or mucous membranes.

Significantly, certain embodiments of the present invention have a verylow potential for generating clinical microbial resistance. Thus, suchcompositions can be applied multiple times over one or more days totreat topical infections or to eradicate unwanted bacteria (such asnasal colonization of Staphylococcus aureus). Furthermore, compositionsof the present invention can be used for multiple treatment regimens onthe same patient without the fear of generating antimicrobialresistance. This can be particularly important for chronically illpatients who are in need of decolonization of the anterior nares beforehemodialysis, for example, or for antiseptic treatment of chronic woundssuch as diabetic foot ulcers.

Also, preferred compositions of the present invention have a generallylow irritation level for skin, skin lesions, and mucosal membranes(including the anterior nares, nasal cavities, and nasopharangylcavity). Also, certain preferred compositions of the present inventionare substantive (i.e. resist removal by fluids) for relatively longperiods of time to ensure adequate efficacy.

Compositions of the present invention include a cationic antiseptic. Thecationic antiseptics include biguanides and bisbiguanides such aschlorhexidine and its various salts including but not limited to thedigluconate, diacetate, dimethosulfate, and dilactate salts as well asmixtures thereof; polymeric quatemary ammonium compounds such aspolyhexamethylenebiguanide; silver and various silver complexes; smallmolecule quatemary ammonium compounds such as benzalkoium chloride andalkyl substituted derivatives, di-long chain alkyl (C8-C18) quaternaryammonium compounds, cetylpyridinium halides and their derivatives,benzethonium chloride and its alkyl substituted derivatives, andoctenidine; and combinations thereof.

Importantly, the compositions of the present invention are capable ofdestroying microorganisms on or in mammalian tissue. Therefore, theconcentrations employed are generally greater than those that have beenused to simply preserve certain topically applied compositions, i.e.,prevent the growth of microorganism in topical compositions for purposesother than antisepsis. For example, the concentration may be at least0.1 wt %, preferably at least 0.2 wt % and more preferably at least 0.5wt %. Commonly, the antiseptics may be employed at concentration of atleast 1 wt-%, preferably at least 2 wt-% and often at least 3% by weightof the composition. All weight percents are based on the total weight ofa “ready to use” or “as used” composition.

Depending on the application, many of these compounds at theseconcentrations can be irritating if delivered in simple aqueous orhydrophilic vehicle formulations. Many of the compositions of thepresent invention incorporate a substantial amount of a lipophilic orhydrophobic phase. The hydrophobic phase is comprised of one or morewater insoluble components. If delivered in a hydrophobic phase, theirritation can be significantly reduced. The incorporation of thehydrophobic phase may significantly reduce the irritation potential ofthe present compositions. Preferred lipophilic phase components have asolubility in water of less than 0.5% by weight and often less 0.1% byweight at 23° C. In addition, the antiseptic is preferably present at aconcentration approaching or preferably exceeding the solubility limitof the hydrophobic phase.

Importantly, the compositions also have sufficient viscosity to preventinhalation into the lungs if used in the nose for applications such asnasal decolonization. The relatively high viscosity of the compositionsof the present invention also minimizes migration that can be associatedwith other compositions thus reducing irritation and mess. Despite thepresence of the hydrophobic phase many of the antiseptic containingcompositions exhibit very effective and rapid antimicrobial activity.

In addition, antimicrobial compositions that include hydrophiliccomponents such as polyols (e.g., glycerin and polyethylene glycols)that themselves have little or no antimicrobial activity canconsiderably enhance the antimicrobial activity of the compositions.Preferably, the hydrophilic component includes a glycol, a lower alcoholether, a short chain ester, and combinations thereof, wherein thehydrophilic component is soluble in water in an amount of at least 20wt-% at 23° C.

The compositions of the present invention are preferably free ofantibiotics.

Preferably, the compositions also include a surfactant selected from thegroup of sulfonate, a sulfate, a phosphonate, a phosphate, amphoteric, apoloxamer, a cationic surfactant, or mixtures thereof. Preferably, thecompositions also include an enhancer component comprising analpha-hydroxy acid, a beta-hydroxy acid, a chelating agent, a(C1-C4)alkyl carboxylic acid, a (C6-C12)aryl carboxylic acid, a(C6-C12)aralkyl carboxylic acid, a (C6-C12)alkaryl carboxylic acid, aphenolic compound, a (C1-C10)alkyl alcohol, an ether glycol, orcombinations thereof.

The present invention also provides various methods of use ofcompositions of the present invention. In one embodiment, the presentinvention provides a method of preventing and/or treating an afflictioncaused, or aggravated by, a microorganism on mammalian tissue, such asskin and/or a mucous membrane. The method includes contacting themammalian tissue with an antimicrobial composition of the presentinvention.

In one embodiment, the present invention provides a method ofdecolonizing at least a portion of the nasal cavities, anterior nares,and/or nasopharynx of a subject of microorganisms. The method includescontacting the nasal cavities, anterior nares, and/or nasopharynx withan antimicrobial composition of the present invention in an amounteffective to kill one or more microorganisms in or on tissue.

In one embodiment, the present invention provides a method ofdecolonizing at least a portion of the throat/esophagus of a subject ofmicroorganisms. The method includes contacting the esophageal cavitywith an antimicrobial composition of the present invention in an amounteffective to kill one or more microorganisms in or on the tissue in thethroat.

In one embodiment, the present invention provides a method ofdecolonizing at least a portion of the throat/esophagus of a subject ofmicroorganisms. The method includes contacting the oral cavity and/ornasal with an antimicrobial composition of the present invention in anamount effective to allow a sufficient quantity of the composition topass down the throat to reduce or eliminate bacterial colonization in oron the tissue in the throat.

In one embodiment, the present invention provides a method ofdecolonizing at least a portion of the oral cavity of a subject ofmicroorganisms. The method includes contacting the oral cavity with anantimicrobial composition of the present invention in an amounteffective to kill one or more microorganisms in or on the soft tissue inthe oral cavity.

In one embodiment, the present invention provides a method of treatingrespiratory afflictions (e.g., chronic sinusitis in a subject. Themethod includes contacting at least a portion of the respiratory system(particularly the upper respiratory system including the nasal cavities,anterior nares, and/or nasopharynx) with an antimicrobial composition ofthe present invention in an amount effective to reduce or eliminatebacterial colonization in or on the soft tissue in the respiratorysystem.

In one embodiment, the present invention provides a method of treatingimpetigo on the skin of a subject. The method includes contacting theaffected area with an antimicrobial composition of the present inventionin an amount effective to reduce or eliminate clinical signs ofinfection.

In other embodiments, the present invention provides methods for killingor inactivating microorganisms. Herein, to “kill or inactivate” means torender the microorganism ineffective by killing them (e.g., bacteria andfungi) or otherwise rendering them inactive (e.g., viruses). The presentinvention provides methods for killing bacteria such as Staphylococcusspp., Streptococcus spp., Escherichia spp., Enterococcus spp. (includingantibiotic resistant strains such as vancomycin resistant Enterococcu),and Pseudamonas spp. bacteria, and combinations thereof, and moreparticularly Staphylococcus aureus (including antibiotic resistantstrains such as methicillin resistant Staphylococcus aureus),Staphylococcus epidermidis, Escherichia coli (E. coli), Pseudomonasaeruginosa (Pseudomonas ae.), and Streptococcus pyogenes, which oftenare on or in the skin or mucosal tissue of a subject. The methodincludes contacting the microorganism with an antimicrobial compositionof the present invention in an amount effective to kill one or moremicroorganisms (e.g., bacteria and fungi) or inactivate one or moremicroorganisms (e.g., viruses, particularly herpes virus).

For example, in one embodiment, the present invention provides a methodof killing or inactivating microorganisms in the nose or nasal cavity ofa subject. The method includes contacting the affected area with anantimicrobial composition of the present invention in an amounteffective to kill one or more microorganisms on or in the tissue in thenose or nasal cavity.

The compositions of the present invention can also be used for providingresidual antimicrobial efficacy on a surface that results from leaving aresidue or imparting a condition to the surface (e.g., skin, in theanterior nares, mucosal tissue, wound, or medical device that comes incontact with such tissues, but particularly skin, mucosal tissue, and/orwound) that remains effective and provides significant antimicrobialactivity. This is accomplished by providing compositions with relativelyhigh concentrations of a hydrophobic component (generally greater than30% by weight, preferably greater than 40% by weight and most preferablygreater than 50% by weight) and/or a composition with a relatively highviscosity, e.g., in excess of 1,000 cps and preferably in excess of10,000 cps when measured by the Viscosity Test.

For example, in one embodiment, the present invention provides a methodof providing residual antimicrobial efficacy on the skin, in theanterior nares, mucosal tissue, and/or in a wound of a subject, themethod includes contacting the skin, mucosal tissue, and/or wound withan antimicrobial composition of the present invention in an amounteffective to kill one or more microorganisms.

Methods of manufacture are also provided.

DEFINITIONS

The following terms are used herein according to the followingdefinitions.

“Effective amount” means the amount of the one or more antisepticcomponents when in a composition, as a whole, provides antimicrobial(including, for example, antiviral, antibacterial, or antifungal)activity that when applied in an amount, at a frequency, and for aduration, reduces, prevents, or eliminates one or more species ofmicrobes such that an acceptable level of the microbe results.Typically, this is a level low enough not to cause clinical symptoms,and is desirably a non-detectable level. It should be understood that inthe compositions of the present invention, the concentrations or amountsof the components, when considered separately, may not kill to anacceptable level, or may not kill as broad a spectrum of undesiredmicroorganisms, or may not kill as fast; however, when used togethersuch components provide an enhanced antimicrobial activity (as comparedto the same components used alone under the same conditions). Also, itshould be understood that (unless otherwise specified) the listedconcentrations of the components are for “ready to use” or “as used”compositions. The compositions can be in a concentrated form. That is,certain embodiments of the compositions can be in the form ofconcentrates that would be diluted by the user with an appropriatevehicle.

“Hydrophilic” or “water-soluble” refers to a material that will disperseor dissolve tin deionized water (or other aqueous solution as specified)at a temperature of 23° C. in an amount of at least 7% by weight,preferably at least 10% by weight, more preferably at least 20% byweight, even more preferably at least 25% by weight, even morepreferably at least 30% by weight, and most preferably at least 40% byweight, based on the total weight of the hydrophilic material and thewater. The component is considered dissolved if after thoroughly mixingthe compound with water at 60° C. for at least 4 hours and allowing thisto cool to 23-25° C. for 24 hours, and mixing the composition thoroughlyit appears uniform clear solution without visible cloudiness, phaseseparation, or precipitate in a jar having a path length of 4 cm.Typically when placed in 1×1 cm cell, the samples exhibit greater than70% transmission measured in a suitable spectrophotometer at awavelength of 655 nm. Water dispersible hydrophilic materials dispersein water to form uniform cloudy dispersions after vigorous shaking of a5% by weight mixture of the hydrophilic component in water. Preferredhydrophilic components are water-soluble.

“Hydrophobic” or “water-insoluble” refers to a material that will notsignificantly dissolve in deionized water at 23° C. “Not significantly”means that the solubility in water of the material is less than 5% byweight, preferably less than 1% by weight, more preferably less than0.5% by weight, and even more preferably less than 0. 1% by weight,based on the total weight of the hydrophobic material and the water.Solubility can be determined by thoroughly mixing the compound withwater at the appropriate concentration at 23° C. for at least 24 hours(or at elevated temperature if that is necessary to dissolve thecompound), allowing this to sit at 23-25° C. for 24 hours, and observingthe sample. In a glass jar with a 4 cm path length the sample shouldhave evidence of a second phase which can be liquid or solid and may beseparated on the top, bottom, or distributed throughout the sample. Forcrystalline compounds care must be taken to avoid producing asupersaturated solution. The components should be mixed and observed.Cloudiness or presence of a visible precipitate or separate phaseindicates that the solubility limit has been exceeded. Typically whenplaced in 1×1cm cell the sample has less than 70% transmission measuredin a suitable spectrophotometer at a wavelength of 655 nm. Forsolubility determinations less than that which can be observed with thenaked eye, the solubility is determined using radiolabeled compounds asdescribed under “Conventional Solubility Estimations” in Solubility ofLong-Chain Fatty Acids in Phosphate Buffer at pH 7.4, Henrik Vorum, et.al., Biochimica et. Biophysica Acta. 1126 (1992) 135-142.

“Stable” means physically stable or chemically stable, which are bothdefined in greater detail below. Preferred compositions are bothchemically and physically stable.

“Microorganism” “microbe” refers to bacteria, yeast, mold, fungi,protozoa, mycoplasma, as well as viruses (including lipid enveloped RNAand DNA viruses).

“Antibiotic” means an organic chemical compound produced bymicroorganisms that has the ability in dilute concentrations to destroyor inhibit microorganisms and is used to treat infectious disease. Thismay also encompass semi-synthetic compounds that are chemicalderivatives of the compound produced by microorganisms or syntheticcompounds that act on very specific biochemical pathways necessary forthe cell's survival.

“Antiseptic” means a chemical agent other than the “enhancers” describedherein that kills pathogenic and non-pathogenic microorganisms.Preferred antiseptics exhibit at least 4 log reduction of both P.aeruginosa and S. aureus in 60 minutes from an initial inoculum of1-3×10⁷ cfu/ml when tested in Mueller Hinton broth at 35° C. at aconcentration of 0.25 wt % in a Rate of Kill assay using an appropriateneutralizer as described in The Antimicrobial Activity in vitro ofchlorhexidine, a mixture of isothiazolinones (Kathon CG) and cetyltrimethyl ammonium bromide (CTAB), G. Nicoletti, V. Boghossian, F.Gurevitch, R. Borland and P. Mogenroth, Journal of Hospital Infection,(1993), vol. 23, pp 87-111. Antiseptics generally interfere more broadlywith the cellular metabolism and/or the cell envelope. Antiseptics maybe small molecule or polymeric. Small molecule antiseptics generallyhave molecular weights less than about 350 g/mole. Polymeric antisepticscan be much higher in molecular weight.

“Enhancer” means a component that enhances the effectiveness of theantiseptic component such that when the composition less the antisepticcomponent and the composition less the enhancer component are usedseparately, they do not provide the same level of antimicrobial activityas the composition as a whole. For example, an enhancer component in theabsence of the antiseptic component may not provide any appreciableantimicrobial activity. The enhancing effect can be with respect to thelevel of kill, the speed of kill, and/or the spectrum of microorganismskilled, and may not be seen for all microorganisms. In fact, an enhancedlevel of kill is most often seen in Gram negative bacteria such asEscherichia coli. An enhancer may be a synergist such that when combinedwith the remainder of the composition, the composition as a wholedisplays an activity that is greater than the sum of the activity of thecomposition less the enhancer component and the composition less theantiseptic component.

“Mucous membranes,” “mucosal membranes,” and “mucosal tissue” are usedinterchangeably and refer to the surfaces of the nasal (includinganterior nares, nasoparangyl cavity, etc.), oral (e.g., mouth), outerear, middle ear, vaginal cavities, and other similar tissues. Examplesinclude mucosal membranes such as buccal, gingival, nasal, ocular,tracheal, bronchial, gastrointestinal, rectal, urethral, ureteralvaginal, cervical, and uterine mucosal membranes.

“Preservative” as used herein refers to antiseptics which areincorporated into a composition to prevent biological contaminationand/or deterioration of a composition. These are generally present atlevels of less than 0.50 by weight and often less than about 0.1% byweight.

“Affliction” means a condition to a body resulting from sickness,disease, injury, bacterial colonization, etc.

“Treat” or “treatment” means to improve the condition of a subjectrelative to the affliction, typically in terms of clinical symptoms ofthe condition.

“Decolonization” refers to a reduction in the number of microorganisms(e.g., bacteria and fungi) present in or on tissue that do notnecessarily cause immediate clinical symptoms. Examples ofdecolonization include, but are not limited to, decolonization of thenasal cavity and wounds. Ordinarily fewer microorganisms are present in“colonized tissue” than in “infected tissue.” When the tissue iscompletely decolonized the microorganisms have been “eradicated”.

“Subject” and “patient” includes humans, sheep, horses, cattle, pigs,dogs, cats, rats, mice, or other mammal.

“Wound” refers to an injury to a subject which involves a break in thenormal skin or mucosal tissue barrier exposing tissue below, which iscaused by, for example, lacerations, surgery, burns, damage tounderlying tissue such as pressure sores, poor circulation, and thelike. Wounds are understood to include both acute and chronic wounds.

The terms “comprises” and variations thereof do not have a limitingmeaning where these terms appear in the description and claims.

As used herein, “a,” “an,” “the,” “at least one,” and “one or more” areused interchangeably. The term “and/or” means one or all of the listedelements (e.g., preventing and/or treating an affliction meanspreventing, treating, or both treating and preventing furtherafflications).

Also herein, the recitations of numerical ranges by endpoints includeall numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2,2.75, 3, 3.80, 4, 5, etc.).

The above summary of the present invention is not intended to describeeach disclosed embodiment or every implementation of the presentinvention. The description that follows more particularly exemplifiesillustrative embodiments. In several places throughout the application,guidance is provided through lists of examples, which examples can beused in various combinations. In each instance, the recited list servesonly as a representative group and should not be interpreted as anexclusive list.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The present invention provides antimicrobial (including, e.g.,antiviral, antibacterial, and antifungal) compositions. Thesecompositions include one or more antiseptics selected from the groupconsisting of biguanides and bisbiguanides such as chlorhexidine and itsvarious salts including but not limited to the digluconate, diacetate,dimethosulfate, and dilactate salts as well as combinations thereof;polymeric quaternary ammonium compounds such aspolyhexamethylenebiguanide; silver and various silver complexes; smallmolecule quaternary ammonium compounds such as benzalkoium chloride andalkyl substituted derivatives; di-long chain alkyl (C8-C18) quaternaryammonium compounds; cetylpyridinium halides and their derivatives;benzethonium chloride and its alkyl substituted derivatives; andoctenidine. The antiseptics are present in sufficient concentration (atleast 0.20 wt-% and typically greater than 0.30 wt-% and most preferablygreater than 0.50% by weight) which when applied to mammalian tissue foran adequate time, for an adequate frequency, and in an adequate dose arecapable of decolonizing or eradicating microorganisms from the tissue.Certain compositions also include one or more surfactants, one or morehydrophilic compounds, and/or one or more hydrophobic compounds.

Such compositions preferably adhere well to bodily tissues (e.g., skin,mucosal tissue, and wounds) and thus are very effective topically.Importantly, the compositions, however, are not bioadhesive and thuswill not bond tissue together. Thus, the present invention provides awide variety of uses of the compositions. Particularly preferred methodsinvolve topical application, particularly to mucosal tissues (i.e.,mucous membranes including the anterior nares and other tissues of theupper respiratory tract), as well as skin (e.g., skin lesions) andwounds.

For certain applications in which broad spectrum antimicrobial activityis desired, compositions containing multiple antiseptics can be used. Inother applications in which limited antimicrobial activity is desired,compositions containing an antiseptic with limited spectrum may beemployed. For example, in certain situations it may be desirable to killor inactivate only one type or a few types of microorganism as opposedto all the microorganisms present. For example, many quaternary ammoniumcompounds have much higher minimum inhibitory concentrations againstGram-negative organisms compared to gram positive microorganisms andthus may be employed in situations where it is desirable to kill mainlythe Gram-positive organisms. This may be useful in nasal decolonization,treatment of impetigo and in other topical infections caused primarilyby Gram-positive organisms.

Compositions of the present invention can be used to provide effectivetopical antimicrobial activity and thereby treat and/or prevent a widevariety of afflictions. For example, they can be used in the treatmentand/or prevention of afflictions that are caused, or aggravated by,microorganisms (e.g., Gram positive bacteria, Gram negative bacteria,fungi, protozoa, mycoplasma, yeast, viruses, and even lipid-envelopedviruses) on skin and/or mucous membranes, such as those in the nose(anterior nares, nasopharyngeal cavity, nasal cavities, etc.), outerear, middle ear, mouth, rectum, vagina, or other similar tissue.Particularly relevant organisms that cause or aggravate such afflictionsinclude Staphylococcus spp., Streptococcus spp., Pseudomonas spp.,Enterococcus spp., and Esherichia spp., bacteria, as well as herpesvirus, Aspergillus spp., Fusarium spp., and Candida spp. Particularlyvirulent organisms include Staphylococcus aureus (including resistantstrains such as Methicillin Resistant Staphylococcus Aureus (MRSA),Staphylococcus epidermidis, Streptococcus pneumoniae, Enterococcusfaecalis, Vancomycin Resistant Enterococcus (VRE), Pseudomonasauerginosa, Escherichia coli, Aspergillus niger, Aspergillus fumigatus,Aspergillus clavatus, Fusarium solani, Fusarium oxysporum, Fusariumchlamydosporum, Candida albicans, Candida glabrata, and Candida krusei.

Compositions of the present invention can be used for the preventionand/or treatment of one or more microorganism-caused infections or otherafflictions. In particular, compositions of the present invention can beused for preventing and/or treating one or more of the following: skinlesions, conditions of the skin such as impetigo, eczema, diaper rash ininfants as well as incontinent adults, inflammation around ostomydevices, shingles, and bacterial infections in open wounds (e.g., cuts,scrapes, burns, lacerations, chronic wounds); necrotizing faciitis;infections of the outer ear; acute or chronic otitis media (middle earinfection) caused by bacterial, viral, or fungal contamination; fungaland bacterial infections of the vagina or rectum; vaginal yeastinfections; bacterial rhinitis; ocular infections; cold sores; genitalherpes; colonization by Staphylococcus aureus in the anterior nares(e.g. prior to surgery or hemodialysis); mucositis (i.e., inflammationas opposed to infection of a mucous membrane typically induced bynon-invasive fungus); chronic sinusitis (e.g., that caused by bacterialor viral contamination); non-invasive fungus-induced rhinosinusitis;chronic colitis; Crohn's disease; burns; napkin rash; tinea pedis (i.e.,athlete's foot); tinea curis (i.e., jock itch); tinea corporis (i.e.,ringworm); candidiasis; strep throat, strep pharyngitis, and other GroupA Streptococci infections; rosacea (often called adult acne); commoncold; and respiratory afflictions (e.g., asthma). In sum, compositionsof the present invention can be used for preventing and/or treating awide variety of topical afflictions caused by microbial infection (e.g.,yeast, viral, bacterial infections).

Compositions of the present invention can be used on a wide variety ofsurfaces. For example, they can be used on skin, mucosal tissue, chronicwounds, acute wounds, burns and the like. They can also be deliveredfrom swabs, cloth, sponges, foams and non-woven and paper products(e.g., paper towels and wipes), for example where they are used todeliver a significant portion of the antiseptic composition to thetissue. By “significant portion” it is meant that enough composition isapplied and allowed to remain on the tissue when applied in a dose, at afrequency, and in an amount sufficient to reduce or eliminate themicroorganisms on or in the tissue.

Thus, the present invention also provides various methods of use ofcompositions of the present invention. Various embodiments of thepresent invention include: a method of preventing an affliction caused,or aggravated by, a microorganism on skin and/or a mucous membrane; amethod of decolonizing at least a portion of the nasal cavities,anterior nares, and/or nasopharynx of a subject of microorganisms; amethod of eradicating microorganisms from at least a portion of thenasal cavities, anterior nares, and/or nasopharynx of a subject; amethod of treating a middle ear infection in a subject (by introductioninto the middle ear through the Eustachian tube, and/or the tympanicmembrane by diffusion or direct injection); a method of treating chronicsinusitis in a subject (by treating at least a portion of therespiratory system, particularly the upper respiratory system, includingthe nasal cavities, anterior nares, and/or nasopharynx); a method oftreating impetigo on the skin of a subject; a method of treating and/orpreventing an infection on the skin, mucosal tissue, and/or wound of asubject; a method of treating a burn; a method of killing orinactivating microorganisms (e.g., killing bacteria and/or fungi, orinactivating viruses); a method for providing residual antimicrobialefficacy (e.g., antibacterial, antfungal, and/or antiviral efficacy)that results from leaving a residue or imparting a condition on asurface (such as skin, mucosal tissue, wound, and/or medical device thatcontacts such surfaces) that remains effective and provides significantantimicrobial activity. Not all of the antiseptics disclosed herein areuseful for all of these conditions. Suitable indications for eachantiseptic are discussed below.

It should be understood that compositions of the present invention canbe used in situations in which there are no clinical indications of anaffliction. For example, compositions of the present invention can beused in methods of decolonizing at least a portion of the nasal cavities(i.e., space behind the vestibule of the nose), anterior nares (i.e.,the opening in the nose to the nasal cavities, also referred to as theexternal nares), and/or nasopharynx (i.e., the portion of the pharynx,i.e., throat, that lies above the point of food entry into the pharynx)of a subject of microorganisms. A suitable in vivo model to test for theeffectiveness of compositions to decolonize the anterior nares has beenestablished and is described by K. Kiser et al., Infect and Immunity,67(10), 5001-5006 (1999). Compositions of the present invention can alsobe used to decolonize microorganisms from wounds. Also disclosed in theexample section is an in-vitro model that places microorganisms incontact with a static coating of the antimicrobial composition. Thistest method is suitable for comparing the potential efficacy ofcompositions of the present invention for most topical antisepticapplications including nasal decolonization.

Decolonization methods using compositions of the present invention areparticularly useful in immunocompromised patients (including oncologypatients, diabetics, HIV patients, transplant patients an the like),particularly for fungi such as Aspergillus spp. and Fusarium spp.

In particular, compositions of the present invention can be used inchronic wounds to eliminate methicillin-resistant Staphylococcus aureusand vancomycin resistant enterococcus, which may or may not showclinical signs of infection such as inflammation, pus, exudate, etc.Also, certain compositions of the present invention can killlipid-enveloped viruses, which can be very difficult to kill and cancause shingles (Herpes), chronic sinusitis, otitis media, and otherlocal diseases.

Those of ordinary skill in the art will readily determine when acomposition of the present invention provides antimicrobial activityusing assay and bacterial screening methods well known in the art. Onereadily performed assay involves exposing selected known or readilyavailable viable microorganism strains, such as Enterococcus spp.,Aspergillus spp., Escherichia spp., Staphylococcus spp., Streptococcusspp., Pseudomonas spp., or Salmonella spp., to a test composition at apredetermined bacterial burden level in a culture media at anappropriate temperature. For the preferred compositions of the presentinvention this is most conveniently done by the Antimicrobial EfficacyTest described in the Examples Section. Briefly, the antimicrobialcomposition is coated onto a sterile surface and a bacterial suspensionis distributed directly on the surface of the composition. After asufficient contact time, the sample containing the exposed bacteria iscollected, placed in neutralizing broth, a sample is taken and diluted,and plated out on agar. The plated sample is incubated at an appropriatetemperature and humidity for forty-eight hours and the number of viablebacterial colonies growing on the plate is counted. Once colonies havebeen counted the reduction in the number of bacteria caused by the testcomposition is readily determined. Bacterial reduction is generallyreported as log₁₀ reduction determined by the difference between thelog₁₀ of the initial inoculum count and the log₁₀ of the inoculum countafter exposure. Preferred compositions of the present invention have anaverage of at least a 2 log reduction in test bacteria in 10 minutes,and preferably in 2.5 minutes.

Many of the preferred compositions were tested as described in theExamples Section for antimicrobial activity against MRSA (Gram positive,ATCC Number 16266) and E. coli (Gram negative, ATCC Number 11229).Preferred compositions of the present invention also exhibit very rapidantimicrobial activity. As shown in the Examples Section, preferredformulations are able to achieve an average log reduction of at least 4log against at least one of these two organisms after a 10 minuteexposure and preferably after a 2.5 minute exposure. More preferredcompositions are able to achieve an average log reduction of at least 5log and even more preferred at least 6 log against at least one of thesetwo organisms after a 10 minute exposure and preferably after a 2.5minute exposure.

For residual antimicrobial efficacy, compositions of the presentinvention preferably maintain an average log reduction of at least 1log, more preferably at least 1.5 log, and even more preferably at least2 log, for at least 1 hour, more preferably at least 3 hours, and evenmore preferably at least 24 hours after application to an affected siteor after testing the composition on the forearm of a subject. To testthis, a composition was applied to the forearm of a subject as a uniformwet coating in an amount of approximately 4 milligrams per squarecentimeter (mg/cm²) to the forearm of a healthy subject and allowed toremain on the skin for typically a minimum of 10 minutes over an area ofapproximately 5×5 cm. The composition was gently washed with 23° C.normal saline (0.9% by weight sodium chloride). The saline washed sitewas exposed to a known quantity of bacteria in an inoculum of about 10⁶bacteria/ml (typically Staphylococcus epidermidis or E. coli) for 30minutes. The bacteria were recovered and treated with an effectiveneutralizer and incubated to quantify the bacteria remaining.Particularly preferred compositions retain at least 1 log reduction andpreferably at least 2 log reduction of bacteria after a gentle rinsewith 500 ml saline poured over the site by placing the saline containeras close the site as possible so as to not have the saline fall onto thesite.

Importantly, certain embodiments of the present invention have a verylow potential for generating microbial resistance. For example,preferred compositions of the present invention have an increase in theratio of final to initial MIC levels (i.e., minimum inhibitoryconcentration) of less than 16, more preferably less than 8, and evenmore preferably less than 4. Such an emergence of resistance assayshould be carried out such that the microorganisms are subjectedinitially to sub MIC levels (e.g. ½t he MIC) of antiseptic and after 24hours the microorganisms passed into broth containing twice theconcentration of antiseptic. This is repeated for 8 days and each daymicroorganisms are removed to determine the new MIC. Thus, such lowresistance forming compositions can be applied multiple times over oneor more days to treat topical infections or to eradicate unwantedbacteria (such as nasal colonization of Staphylococcus aureus).

Preferred compositions of the present invention contain an effectiveamount of cationic antiseptic to rapidly kill or inactivatemicroorganisms on skin, skin lesions, and mucosal membranes. In certainembodiments, essentially all the microorganisms are eradicated orinactivated within five days, preferably within three days, morepreferably two days, and most preferably within 24 hours using one ormore doses.

Preferred compositions of the present invention have a generally lowirritation level for skin, skin lesions, and mucosal membranes(including the anterior nares, nasal cavities, nasopharyngeal cavity andother portions of the upper respiratory tract). For example, certainpreferred compositions of the present invention are no more irritatingthan BACTROBAN ointment (on skin) or BACTROBAN NASAL (in the anteriornares) products available from Glaxo Smith Kline.

Preferred compositions of the present invention are substantive forrelatively long periods of time to ensure adequate efficacy. Forexample, certain compositions of the present invention remain at thesite of application with antimicrobial activity for at least 1 hour,preferably at least 4 hours, and more preferably at least 8 hours. Thiscan be easily determined by swabbing the site after a predetermined timeand testing for the antimicrobial active by a suitable analyticaltechnique such as gas chromatography (GC) or high performance liquidchromatography (HPLC).

Preferred compositions of the present invention are physically stable.As defined herein “physically stable” compositions are those that do notsignificantly change due to substantial precipitation, crystallization,phase separation, and the like, from their original condition duringstorage at 23° C. for at least 3 months, and preferably for at least 6months. Particularly preferred compositions are completely physicallystable if a 10-milliliter (10-ml) sample of the composition when placedin a 15-ml conical-shaped graduated plastic centrifuge tube (Coming) andcentrifuged at about 2275×g (e.g. 3,000 revolutions per minute (rpm) for10 minutes using a Labofuge B, model 2650 manufactured by HeraeusSepatech GmbH, Osterode, West Germany) or similar centrifuge at acentrifugal force of 2275×g has no visible phase separation in thebottom or top of the tube. Phase separation of less than 0.5 ml is alsoconsidered stable as long as there is no other sign of physicalseparation in the sample.

Preferred compositions of the present invention exhibit good chemicalstability. This can be especially a concern with compounds that mayhydrolyze or undergo heat and/or light degradation such aschlorhexidine. The most preferred compositions retain an average of atleast 97% of the antiseptic component after aging for 4 weeks at 40° C.in a sealed container beyond the initial 5-day equilibration period at23° C. The percent retention is understood to mean the weight percent ofantiseptic component retained. This is determined by comparing theamount remaining in a sample aged (i.e., aged beyond the initial 5-dayequilibration period) in a sealed container that does not causedegradation, to the actual measured level in an identically preparedsample (preferably from the same batch) and allowed to sit at 23° C. forfive days. The level of antiseptic component is preferably determinedusing gas chromatography or high performance liquid chromatography.

Generally, the compositions of this invention may be in one of thefollowing forms:

-   -   A hydrophobic ointment: The compositions are formulated with a        hydrophobic base (e.g., petrolatum, thickened or gelled water        insoluble oils and the like) and optionally having a minor        amount of a water-soluble phase.    -   An oil in water emulsion: The compositions may be formulations        in which the antiseptic is emulsified into an emulsion        comprising a discrete phase of a hydrophobic component and a        continuous aqueous phase comprising water and optionally one or        more polar hydrophilic carrier as well as salts, surfactants,        emulsifiers, or other components. These emulsions may comprise        water-soluble or water swellable polymers as well as one or more        emulsifiers that help to stabilize the emulsion. These emulsions        generally have higher conductivity values as described in U.S.        Ser. No. 09/966,511.    -   A water in oil emulsion: The compositions may be formulations in        which the antiseptic is incorporated into an emulsion comprising        a continuous phase of a hydrophobic component and an aqueous        phase comprising water and optionally one or more polar        hydrophilic carrier as well as salts or other components. These        emulsions may comprise oil soluble or oil swellable polymers as        well as one or more emulsifiers that help to stabilize the        emulsion.    -   Thickened aqueous gels: These systems are comprised of an        aqueous phase that has been thickened to achieve a viscosity in        excess of 500 cps and preferably greater than 5000 cps. Most        preferred systems have a viscosity in excess of 10,000 cps, more        preferably greater than 25,000 cps and most preferably greater        than 50,000 cps. The viscosity is determined using the Viscosity        Test described herein. These systems comprise the antiseptics        described here in and are thickened by suitable natural,        modified natural, or synthetic polymers as described below. The        thickened aqueous gels can also be thickened using suitable        emulsifiers such as alkyl alcohols and polyethoxylated alkyl        chain surfactants that effectively thicken the composition.        Examples include the Polawax, Behenyl TMS, Crodaphos CES,        Cosmowax, and Crothix systems from Croda Inc.    -   Hydrophilic gels: These are systems in which the continuous        phase is comprised of at least one water soluble hydrophilic        component other than water. The formulations may optionally also        contain water up to about 20% by weight. Higher concentrations        may be suitable in some compositions. Suitable hydrophilic        components include one or more glycols (such as glycerin,        propylene glycol, butylenes glycol, etc.), polyethylene glycols        (PEG), random or block copolymers of ethylene oxide, propylene        oxide, and/or butylenes oxide, polyalkoxylated surfactants        having one or more hydrophobic moieties per molecule, silicone        copolyols, as well as combinations thereof. One skilled in the        art will recognize that the level of ethoxylation must be        sufficient to render the hydrophilic component water-soluble or        water dispersible at 23° C. In most embodiments, the water        content is less than 10 wt-% and more preferably less than about        5% by weight of the composition.

In most embodiments, the compositions have a viscosity of at least 20cps, preferably greater than 100 cps, more preferably greater than 1000cps, even more preferably greater than 10,000 cps and most preferablygreater than 25,000 cps when measured by the Viscosity Test describedherein. Higher viscosities are preferred to reduce migration as well asto provide substantivity (resistance to removal by fluids) to ensurelong-term antimicrobial activity. Most preferred compositions haveviscosities in excess of 50,000 cps and most preferably in excess of100,000 cps at 23-25° C. when measured by the Viscosity Test. Mostpreferred compositions meet these viscosity values even after heating to32° C., 35° C. or as high as 37° C. to ensure when in contact withmammalian tissue the compositions remain substantive.

Antiseptic Component

The antiseptic component is that component of the composition thatprovides at least part of the antimicrobial activity. That is, theantiseptic component has at least some antimicrobial activity for atleast one microorganism. It is generally considered the main activecomponent of the compositions of the present invention. The antisepticcomponent includes an effective amount of one or more antisepticsselected from the group consisting of biguanides and bisbiguanides suchas chlorhexidine and its various salts including but not limited to thedigluconate, diacetate, dimethosulfate, and dilactate salts, as well ascombinations thereof, polymeric quaternary ammonium compounds such aspolyhexamethylenebiguanide; silver and various silver complexes; smallmolecule quaternary ammonium compounds such as benzalkoium chloride andalkyl substituted derivatives; di-long chain alkyl (C8-C18) quaternaryammonium compounds; cetylpyridinium halides and their derivatives;benzethonium chloride and its alkyl substituted derivatives; octenidineand compatible combinations thereof. The classes of cationic antisepticsare discussed further below.

Biguanides and Bisbiguanides:

This class of antiseptics is represented by the formula:R—NH—C(NH)—NH—C(NH)—NH(CH₂)_(n)NHC(NH)—NH—C(NH)—NH—RWhere n=3-10, preferably 4-8, and most preferably 6; and R═C4-C18branched or straight chain alkyl optionally substituted in availablepositions by halogen or C6-C12 aryl or alkaryl optionally substituted inavailable positions by halogen.

The preferred compound of this class is chlorhexidine. This may bepresent as the free base but is preferably present as a disalt ofacetate, gluconate, lactate, methosulfate (CH₃OSO₃ ⁻), or a halide orcombinations thereof. Most preferred are the diacetate, digluconate,dilactate, and dimethosulfate salts since these salts all havesolubility limits in excess of 1 g/100 ml. For example, the solubilitylimit of the digluconate salt is 20 g/100 ml and that of the diacetateis 1.9 g/100 ml. The most preferred compound is chlorhexidinedigluconate (CHG). Other anions may be useful. It is particularlyimportant, however, with this class as well as other cationicantiseptics to use a counter ion that ensures solubility in aqueousfluid above the minimum inhibitory concentration (MIC) of the treatmentorganism. If the solubility limit is less than the MIC treatment may beineffective.

The antiseptics of this class are particularly preferred in formulationsthat are non-aqueous and protected from light. This is believed toreduce the degradation of the compound. When used in compositionscomprising less than about 20% by weight water, antiseptics of thisclass are preferably formulated with a hydrophilic carrier thatsolublizes the antiseptic. Examples of suitable solvents forchlorhexidine gluconate include glycols (compounds having at least twohydroxylgroups per molecule) such as PEGs having a molecular weightbelow 2000 and preferably less than 1000 and most preferably less thanabout 800 daltons; glycerin and polyglycerols, propylene glycol,dipropylene glycol, tripropyelne glycol, polypropylene glycol, ethyleneoxide/propylene oxide random or block copolymers, trimethylolpropane,pentraerithiritol, sorbitol, panetothenol, glucuronolactone, gluconicacid, and the like as well as other polar solvents such as N-methylpyrrolidone, propylene carbonate, butyrolactone and the like.

Care must also be taken when formulating chlorhexidine as well as othercationic antiseptic compounds to avoid inactivation by sequestering itin micelles which may be formed by incorporation of surfactants and/oremulsifiers. Preferred formulations are hydrophilic ointments; aqueoussolutions thickened with polymeric thickeners that are either surfactantfree or contain surfactants that do not reduce the activity of the CHG,such as poloxamers; and ointments comprising a major amount of ahydrophobic component and preferably further comprising a hydrophiliccomponent.

Bis(biguanide)s such as chlorhexidine are very basic and capable offorming multiple ionic bonds with anionic materials. For this reason,biguanide-containing compositions are preferably free of anioiniccompounds that can result in precipitation of the antiseptic. For thisreason, thickener systems, if present, are preferably based on non-ionicand/or cationic polymers or emulsifiers. Anionic surfactants useful, forexample, as wetting agents, may also need to be avoided. Certainzwitterionic, very water soluble, or non-precipitating anionicemulsifiers and surfactants may also be useful. Halide salts may need tobe avoided. For example, chlorhexidine digluconate (CHG) willprecipitate rapidly in the presence of halide salts above aconcentration of about 0.1M. Therefore, if a system includes CHG orother antiseptic of this class, and needs to comprise salts forstability or other purposes, preferably gluconate salts such astriethanolamine gluconate or sodium gluconate, are used. In addition, ifan additional antiseptic is incorporated into the composition it ispreferably non-ionic or cationic.

Polymeric Quatemary Amine Compounds

Antimicrobial polymers comprising quaternary amine groups may also beused as the antiseptic of the present invention. These are typicallypolymers having quatemary amine groups with at least one alkyl oraralkyl chain of at least 6 carbon atoms and preferably as least 8carbon atoms. The polymers may be linear, branched, hyperbranched ordendrimers. Preferred antimicrobial polymeric quaternary amine polymersinclude those described in U.S. Pat. Nos. 6,440,405; 5,408,022; and5,084,096; PCT Publication No. WO/02102244; and Disinfection,Sterilization and Preservation, S. Block, 4^(th) ed., 1991, Chapter 13,Lea & Febiger.

A particularly preferred class of polymeric quaternary ammoniumantiseptic compounds are polybiguanides. Compounds of this class arerepresented by the formula:X—R¹—NH—C(NH)—NH—C(NH)—NH-R²—NHC(NH)—NH—C(NH)—NH—R³—XWhere R¹, R², and R³ are bridging groups such as polymethylene groupspreferably having 2 to 10 methylene groups, more preferably 4 to 8methylene groups and most preferably 6 methylene groups. The methylenegroups can be optionally substituted in available positions withhalogen, hydroxyl, or phenyl groups. X is a terminal group and istypically an amine, amine salt, or a dicyandiamide group. The preferredcompound of this class is polyhexamethylene biguanide (PHMB)commercially available as Cosmocil CQ from Aveci, Wilmington, Del.

Compounds of this class are typically used at levels of at least 0.05%by weight, preferably at least 0. 1% by weight and most preferably atleast 0.25% by weight and most preferably at least 0.5% by weight.Compounds of this class are preferably used at levels less than about8%, more preferably less than about 6%, and most preferably less thanabout 4% by weight of the composition. Poly(biguanide) antiseptics suchas PHMB are very basic and are capable of forming multiple ionic bondswith anionic materials. For this reason, biguanide-containingcompositions are preferably free of anionic compounds that can result inprecipitation and/or inactivation of the antiseptic. For this reason,thickener systems, if present, are preferably based on non-ionic and/orcationic polymers or emulsifiers. Anionic surfactants useful, forexample, as wetting agents, may also need to be avoided. Certainzwitterionic, very water soluble, or non-precipitating anionicemulsifiers and surfactants may also be useful. Halide salts also mayneed to be avoided.

Silver and Silver Complexes:

Silver is also known to be an effective antiseptic and has been used increams to treat wounds and other topical infections. Silver may also beuseful for nasal decolonization. The active form of silver ion is Ag+which may be delivered from a variety of well known silver salts andcomplexes including silver zeolites; inorganic silver salts such assilver nitrate, silver chloride, silver sulfate, silver thiosulfate;silver alkyl, aryl, and aralkyl carboxylates (preferred carboxylateanions have less than about 8 carbon atoms such as the acetate, lactate,salicylate, and gluconate salts); silver oxide, colloidal silver,nanocrystalline silver, silver coated microspheres, silver complexedwith various polymers as well as silver delivered from dendrimers asdescribed in U.S. Pat. Nos. 6,579,906 and 6,224,898; and silverantimicrobial complexes such as silver sufadiazine. The silver mayoptionally complexed with primary, secondary, tertiary, and quaternaryamines as well as polymeric forms thereofs, and silver proteincomplexes.

Where skin discoloration is undesireable, certain silver complexes canbe used, such as those disclosed, for example, in U.S. Pat. Nos.6,468,521; 5,326,567; 5,429,819; and 5,326,567. Surprisingly, thesesilver compounds and ions can be delivered from the hydrophobic vehiclecompositions of the present invention. Particularly preferredcompositions have a hydrophilic component incorporated into thecomposition. Silver antiseptics may also be delivered from compositionscomprising hydrophobic component(s) as the vehicle.

Silver containing compositions must be protected from light andprecipitating excipients. For example, some anionic surfactants couldresult in inactivation of the silver. Therefore, preferred wettingagents, penentration enhancers, and/or emulsifiers are non-ionic,cationic or zwitterionic. The anions of the cationic surfactants alsoshould be chosen to prevent inactivation of the silver. Preferredsurfactants are non-ionic and amine funcitonal surfactants (includingprimary, secondary, tertiary and quaternary amine-group-containingsurfactants).

Preferably, the concentration of silver ion in the antisepticcompositions is at least 0.20 wt %, more preferably at least 0.5 wt %and most preferably at least 0.75% by weight. Preferably, the silverconcentration is less than 10 wt %, more preferably less than 8 wt %,and most preferably less than 6% by weight. Silver salts and complexesshould be adjusted accordingly based on molecular weight to achieve thesilver ion concentration in the ranges described, as one skilled in theart understands.

Silver compounds when used in the present compositions are capable ofproducing silver ion when in contact with microorganisms. Examples aresilver salts and silver oxides. Preferred compounds are silver nitrate,silver thiosulfate, silver chloride, silver phosphate, silver sulfate,and silver halide salts.

Small Molecule Quaternary Ammonium Compounds:

This class of compounds typically comprise one or more quaternaryammonium groups wherein attached to the quaternary ammonium group is atleast one C6-C18 linear or branched alkyl or aralkyl chain. Suitablecompounds include those disclosed in Disinfection Sterilization andPreservation, S. Block, 4^(th) ed., 1991, Chapter 13, Lea & Febiger.Particularly preferred compounds of this class have one or two C8-C18alkyl or aralkyl chains and may be represented by the following formula:R¹R²NR³R⁴⁺X⁻Where R¹ and R² are C1-C18 linear or branched alkyl, alkaryl, or aralkylchains that may be substituted in available positions by N, O, or Sprovided at least one R¹ or R² is a C8-C18 linear or branched alkyl,alkaryl, or aralkyl chains that may be substituted in availablepositions by N, O, or S. R³ and R⁴ are C1-C6 alkyl, phenyl, benzyl, orC8-C12 alkaryl groups. R³ and R⁴ may also form a ring such as a pyridinering with the nitrogen of the quaternary ammonium group. X is an anion,preferably a halide, and most preferably Cl− or Br—. Other anions mayinclude methosulfate, ethosulfate, phosphates and the like. Preferredcompounds of this class include mnoalyltrimethylammonium salts,monalkyldimethylbenzyl ammonium salts, dialkyldimethyl ammonium salts,benzethonium chloride, and octenidine.

Examples of preferred quaternary ammonium antiseptics includebenzalkonium halides having an alkyl chain length of C8-C18, morepreferably C12-C16, and most preferably a mixture of chain lengths. Forexample, a typical benzalkonium chloride sample may be comprise of 40%C12 alkyl chains, 50% C14 alkyl chains, and 10% C16 alkyl chains. Theseare commercially available from numerous sources including Lonza(Barquat MB-50); Benzalkonium halides substituted with alkyl groups onthe phenyl ring. A commercially avaible example is Barquat 4250available from Lonza; dimethyldialkylammonium halides where the alkylgroups have chain lengths of C8-C18. A mixture of chain lengths such asmixture of dioctyl, dilauryl, and dioctadecyl may be particularlyuseful. Exemplary compounds are commercially available from Lonza asBardac 2050, 205M and 2250 from Lonza; Cetylpyridinium halides such ascetylpyridinium chloride available from Merrell labs as CepacolChloride; Benzethonium halides and alkyl substituted benzethoniumhalides such as Hyamine 1622 and Hyamine 10× available from Rohm andHaas; octenidine and the like.

The antiseptics are typically added to the compositions at aconcentration of at least 0.50 wt %, more preferably at least 0.75 wt %and most preferably at least 1.0% by weight. Preferably, theconcentration is less than 6 wt %, more preferably less than 4 wt %, andmost preferably less than 3% by weight. The pH of aqueous compositions(or the aqueous phase of these compositions) formulated with theseantiseptics typically range from 3-9 and most preferably from 3.5-7.

The compositions of the present invention include one or moreantiseptics at a suitable level to produce the desired result. Suchcompositions preferably include a total amount of antiseptic of at least0.2 percent by weight (wt-%), more preferably at least 0.25 wt-%, evenmore preferably at least 0.35 wt-%, even more preferably at least 0.5wt-%, and even more preferably at least 1, at least two 2, or even atleast 3 wt-%, based on the total weight of the “ready to use” or “asused” composition. In a preferred embodiment, the antiseptic(s) arepresent in a total amount of no greater than 20 wt-%, more preferably nogreater than 15 wt-%, even more preferably no greater than 10 wt-%, andeven more preferably no greater than 6 wt-%, based on the “ready to use”or “as used” composition. Certain compositions may be higher inconcentration if they are intended to be diluted prior to use.

The antiseptics of this invention may be used alone or in combination inorder to effectively kill microorganisms on tissue. Certain combinationsof antiseptics may be particularly useful while others may result inunstable formulations or inactivation of the antimicrobial activity. Forexample, combination of cationic antiseptics such as biguanides andbisbiguanides, polymeric quaternary ammonium compounds, quaternaryammonium compounds, and silver could be incompatible with alkylcarboxylic acids. On the other hand, other antiseptic combinations mayproduce an enhancement or synergistic effect.

The antiseptics of this invention may be used alone, in combination, orwith other antiseptics in order to effectively kill microorganisms ontissue. Additional antiseptics for use with those described hereininclude peroxides, C6-C14 alkyl carboxylic acids and alkyl estercarboxylic acids, antimicrobial natural oils, and compatiblecombinations thereof as provided in Applicants' copending applicationentitled “Antiseptic Compositions and Methods of Use,” U.S. PatentApplication Publication No. 2006/0051384; diphenyl ethers, phenols,halogenated phenols, bisphenols, resorcinols and its derivatives,anilides, and combinations thereof, provided in Applicants' copendingapplication entitled “Phenolic Antiseptic Compositions and Methods ofUse,” U.S. Patent Application Publication No. 2006/0052452.

Certain combinations of antiseptics may be particularly useful whileothers may result in unstable formulations or inactivation of theantimicrobial activity. For example, combination of cationic antisepticssuch as biguanides and bisbiguanides, polymeric quaternary ammoniumcompounds, quaternary ammonium compounds, and silver may be incompatiblewith alkyl carboxylic acids. On the other hand, other antisepticcombinations may produce a synergistic or enhancing effect.

In certain embodiments, the antiseptics of this invention may optionallybe combined with an effective amount of an antimicrobial lipidantiseptic comprising a (C7-C12)saturated fatty acid ester of apolyhydric alcohol, a (C12-C22)unsaturated fatty acid ester of apolyhydric alcohol, a (C7-C12)saturated fatty ether of a polyhydricalcohol, a (C12-C22)unsaturated fatty ether of a polyhydric alcohol, analkoxylated derivative thereof, or combinations thereof, wherein thealkoxylated derivative has less than 5 moles of alkoxide per mole ofpolyhydric alcohol; with the proviso that for polyhydric alcohols otherthan sucrose, the esters comprise monoesters and the ethers comprisemonoethers, and for sucrose the esters comprise monoesters, diesters, orcombinations thereof, and the ethers comprise monoethers, diethers, orcombinations thereof. Useful antiseptics of this class are furtherdescribed in applicants' copending application “AntimicrobialCompositions and Methods of Use,” U.S. Ser. No. 10/659,571, filed onSep. 9, 2003. As used herein the term “fatty” refers to alkyl andalkylene hydrocarbon chains of odd or even number of carbon atoms fromC6-C18.

To achieve rapid antimicrobial activity, formulations may incorporateone or more antiseptics in the composition approaching or preferablyexceeding the solubility limit in the hydrophobic phase. While notintended to be bound by theory we believe that antiseptics thatpreferably partition into the hydrophobic component are not readilyavailable to kill microorganisms which are almost always in orassociated with an aqueous phase. In most compositions the antiseptic ispreferably incorporated in at least 60%, preferably, 75%, morepreferably 100% and most preferably 120% of the solubility limit of thehydrophobic component at 23 C. This in conveniently determined by makingthe formulation without the antiseptic, separating the phases (e.g. bycentrifugation or other suitable separation technique) and determiningthe solubility limit by addition of progressively greater levels of theantiseptic until precipitation occurs. Alternatively, if the formulationis known one can take the components which will form the lipophilicphase, mix them in the proper proportions, and determine the solubilitylimit. One skilled in the art will realize that creation ofsupersaturated solutions must be avoided for an accurate determination.

Enhancer Component

Compositions of the present invention may include an enhancer to enhancethe antimicrobial activity. The activity enhancement may be especiallyuseful against Gram negative bacteria, such as E. coli and Psuedomonassp. The enhancer chosen preferably affects the cell envelope of thebacteria. While not bound by theory, it is presently believed that theenhancer functions by allowing the antiseptic to more easily enter thecell cytoplasm and/or by facilitating disruption of the cell envelope.The enhancer component may include an alpha-hydroxy acid, a beta-hydroxyacid, other carboxylic acids, a (C1-C4)alkyl carboxylic acid, a(C6-C12)aryl carboxylic acid, a (C6-C12)aralkyl carboxylic acid, a(C6-C12)alkaryl carboxylic acid, a chelator, a phenolic compound (suchas certain antioxidants and parabens), a (C1-C10)monohydroxy alcohol, ora glycol ether (i.e., ether glycol). Various combinations of enhancerscan be used if desired.

The alpha-hydroxy acid, beta-hydroxy acid, and other carboxylic acidenhancers are preferably present in their protonated, free acid form. Itis not necessary for all of the acidic enhancers to be present in thefree acid form, however, the preferred concentrations listed below referto the amount present in the free acid form. Furthermore, the chelatorenhancers that include carboxylic acid groups are preferably presentwith at least one, and more preferably at least two, carboxylic acidgroups in their free acid form. The concentrations given below assumethis to be the case. Chelator enhancers may also comprise phosphate orphosphonic acid groups. If precipitation occurs due to interaction withother composition components alternative enahncers should be considered.While the non-ionic enhancers may be useful for all of the antisepticclasses of this invention the anionic enhancers such as the carboxylicacids and chelators may not be compatible with the cationic antiseptics.If precipitation occurs, alternative enhancers should be employed.

One or more enhancers may be used in the compositions of the presentinvention at a suitable level to produce the desired result. In apreferred embodiment, they are present in a total amount greater than0.01 wt-%, preferably in an amount greater than 0.1 wt %, morepreferably in an amount greater than 0.2 wt %, even more preferably inan amount greater than 0.25 wt % and most preferably in an amountgreater than about 0.4 wt % based on the total weight of the ready touse composition. In a preferred embodiment, they are present in a totalamount of no greater than 20 wt-%, based on the total weight of theready to use composition. Such concentrations typically apply toalpha-hydroxy acids, beta-hydroxy acids, other carboxylic acids,chelating agents, phenolics, ether glycols, and (C5-C10)monohydroxyalcohols. Generally, higher concentrations are needed for(C1-C4)monohydroxy alcohols, as described in greater detail below.

The alpha-hydroxy acid, beta-hydroxy acid, and other carboxylic acidenhancers, as well as chelators that include carboxylic acid groups, arepreferably present in a concentration of no greater than 100 milliMolesper 100 grams of formulated composition. In most embodiments,alpha-hydroxy acid, beta-hydroxy acid, and other carboxylic acidenhancers, as well as chelators that include carboxylic acid groups, arepreferably present in a concentration of no greater than 75 milliMolesper 100 grams, more preferably no greater than 50 milliMoles per 100grams, and most preferably no greater than 25 milliMoles per 100 gramsof formulated composition.

The total concentration of the enhancer component relative to the totalconcentration of the antiseptic component is preferably within a rangeof 10:1 to 1:300, and more preferably 5:1 and 1:10, on a weight basis.

An additional consideration when using an enhancer is the solubility andphysical stability in the compositions. Many of the enhancers discussedherein are insoluble in preferred hydrophobic components such as mineraloil and petrolatum. It has been found that the addition of a minoramount (typically less than 30 wt-%, preferably less than 20 wt-%, andmore preferably less than 12 wt-%) of a hydrophilic component not onlyhelps dissolve and physically stabilize the composition but improves theantimicrobial activity as well. Alternatively, the enhancer may bepresent in excess of the solubility limit provided that the compositionis physically stable. This may be achieved by utilizing a sufficientlyviscous composition that stratification (e.g. settling or creaming) ofthe antiseptic does not appreciably occur.

Alpha-hydroxy Acids. An alpha-hydroxy acid is typically a compoundrepresented by the formula:R⁵(CR⁶OH)_(n)COOHwherein: R⁵ and R⁶ are each independently H or a (C1-C8)alkyl group(straight, branched, or cyclic), a (C6-C12)aryl, or a (C6-C12)aralkyl oralkaryl group (wherein the alkyl group is straight, branched, orcyclic), wherein R⁵ and R⁶ may be optionally substituted with one ormore carboxylic acid groups; and n=1-3, preferably, n=1-2.

Exemplary alpha-hydroxy acids include, but are not limited to, lacticacid, malic acid, citric acid, 2-hydroxybutanoic acid, 3-hydroxybutanoicacid, mandelic acid, gluconic acid, glycolic acid, tartaric acid,alpha-hydroxyethanoic acid, ascorbic acid, alpha-hydroxyoctanoic acid,hydroxycaprylic acid, and salicylic acid as well as derivatives thereof(e.g., compounds substituted with hydroxyls, phenyl groups,hydroxyphenyl groups, alkyl groups, halogens, as well as combinationsthereof). Preferred alpha-hydroxy acids include lactic acid, malic acid,and mandelic acid. These acids may be in D, L, or DL form and may bepresent as free acid, lactone, or partial salts thereof. All such formsare encompassed by the term “acid.” Preferably, the acids are present inthe free acid form. In certain preferred embodiments, the alpha-hydroxyacids useful in the compositions of the present invention are selectedfrom the group consisting of lactic acid, mandelic acid, and malic acid,and mixtures thereof. Other suitable alpha-hydroxy acids are describedin U.S. Pat. No. 5,665,776 (Yu).

One or more alpha-hydroxy acids may be used in the compositions of thepresent invention at a suitable level to produce the desired result. Ina preferred embodiment, they are present in a total amount of at least0.25 wt-%, more preferably, at least 0.5 wt-%, and even more preferably,at least 1 wt-%, based on the total weight of the ready to usecomposition. In a preferred embodiment, they are present in a totalamount of no greater than 10 wt-%, more preferably, no greater than 5wt-%, and even more preferably, no greater than 3 wt-%, based on thetotal weight of the ready to use composition. Higher concentrations maybecome irritating.

The ratio of alpha-hydroxy acid enhancer to total antiseptic componentis preferably at most 10:1, more preferably at most 5:1, and even morepreferably at most 1:1. The ratio of alpha-hydroxy acid enhancer tototal antiseptic component is preferably at least 1:20, more preferablyat least 1:12, and even more preferably at least 1:5. Preferably theratio of alpha-hydroxy acid enhancer to total antiseptic component iswithin a range of 1:12 to 1:1.

Beta-hydroxy Acids. A beta-hydroxy acid is typically a compoundrepresented by the formula:

wherein: R⁷, R⁸, and R⁹ are each independently H or a (C1-C8)alkyl group(saturated straight, branched, or cyclic group), a (C6-C12)aryl, or a(C6-C12)aralkyl or alkaryl group (wherein the alkyl group is straight,branched, or cyclic), wherein R⁷ and R⁸ may be optionally substitutedwith one or more carboxylic acid groups; m=0 or 1; n=1-3 (preferably,n=1-2); and R² is H, (C1-C4)alkyl or a halogen.

Exemplary beta-hydroxy acids include, but are not limited to,beta-hydroxybutanoic acid, tropic acid, and trethocanic acid. In certainpreferred embodiments, the beta-hydroxy acids useful in the compositionsof the present invention are selected from the group consisting ofsalicylic acid, beta-hydroxybutanoic acid, and mixtures thereof. Othersuitable beta-hydroxy acids are described in U.S. Pat. No. 5,665,776(Yu).

One or more beta-hydroxy acids may be used in the compositions of thepresent invention at a suitable level to produce the desired result. Ina preferred embodiment, they are present in a total amount of at least0.1 wt-%, more preferably at least 0.25 wt-%, and even more preferablyat least 0.5 wt-%, based on the total weight of the ready to usecomposition. In a preferred embodiment, they are present in a totalamount of no greater than 10 wt-%, more preferably no greater than 5wt-%, and even more preferably no greater than 3 wt-%, based on thetotal weight of the ready to use composition. Higher concentrations maybecome irritating.

The ratio of beta-hydroxy acid enhancer to total antiseptic component ispreferably at most 10:1, more preferably at most 5:1, and even morepreferably at most 1:1. The ratio of beta-hydroxy acid enhancer to totalantiseptic component is preferably at least 1:20, more preferably atleast 1:15, and even more preferably at least 1:10. Preferably the ratioof beta-hydroxy acid enhancer to total antiseptic component is within arange of 1:15 to 1:1.

In systems with low concentrations of water, or that are essentiallyfree of water, esterification may be the principle route of loss of theenhancer by reaction with, for example, the antiseptic or a hydroxylfunctional hydrophilic component. Thus, certain alpha-hydroxy acids(AHA) and beta-hydroxy acids (BHA) are particularly preferred sincethese are believed to be less likely to esterify by reaction of thehydroxyl group of the AHA or BHA. For example, salicylic acid may beparticularly preferred in certain formulations since the phenolichydroxyl group is a much more acidic alcohol and thus much less likelyto react. Other particularly preferred compounds in anhydrous orlow-water content formulations include lactic, mandelic, malic, citric,tartaric, and glycolic acid. Benzoic acid and substituted benzoic acidswhich do not comprise a hydroxyl group while not an hydroxyl acid isalso preferred due to a reduced tendency to form ester groups.

Other Carboxylic Acids. Carboxylic acids other than alpha- andbeta-carboxylic acids are suitable for use in the enhancer component.These include alkyl, aryl, aralkyl, or alkaryl carboxylic acidstypically having equal to or less than 12 carbon atoms and preferablyless than about 8 carbon atoms. A preferred class of these can berepresented by the following formula:R¹⁰(CR¹¹ ₂)_(n)COOHwherein: R¹⁰ and R¹¹ are each independently H or a (C1-C4)alkyl group(which can be a straight, branched, or cyclic group), a (C6-C12)arylgroup, a (C6-C12) group containing both aryl groups and alkyl groups(which can be a straight, branched, or cyclic group), wherein R¹⁰ andR¹¹ may be optionally substituted with one or more carboxylic acidgroups; and n=0-3, preferably, n=0-2. Preferably, the carboxylic acid isa (C1-C4)alkyl carboxylic acid, a (C6-C12)aralkyl carboxylic acid, or a(C6-C12)alkaryl carboxylic acid.

Exemplary acids include, but are not limited to, acetic acid, propionicacid, benzoic acid, benzylic acid, nonylbenzoic acid, and the like.Particularly preferred is benzoic acid.

One or more carboxylic acids may be used in the compositions of thepresent invention at a suitable level to produce the desired result. Ina preferred embodiment, they are present in a total amount of at least0.1 wt-%, more preferably at least 0.25 wt-%, even more preferably atleast 0.5 wt-%, and most preferably at least 1 wt-%, based on the readyto use concentration composition. In a preferred embodiment, they arepresent in a total amount of no greater than 10 wt-%, more preferably nogreater than 5 wt-%, and even more preferably no greater than 3 wt-%,based on the ready to use composition.

The ratio of the total concentration of carboxylic acids (other thanalpha- or beta-hydroxy acids) to the total concentration of theantiseptic component is preferably within a range of 10:1 to 1:100, andmore preferably 2:1 to 1:10, on a weight basis.

Chelators. A chelating agent (i.e., chelator) is typically an organiccompound capable of multiple coordination sites with a metal ion insolution. Typically these chelating agents are polyanionic compounds andcoordinate best with polyvalent metal ions. Exemplary chelating agentsinclude, but are not limited to, ethylene diamine tetraacetic acid(EDTA) and salts thereof (e.g., EDTA(Na)₂, EDTA(Na)₄, EDTA(Ca),EDTA(K)₂), sodium acid pyrophosphate, acidic sodium hexametaphosphate,adipic acid, succinic acid, polyphosphoric acid, sodium acidpyrophosphate, sodium hexametaphosphate, acidified sodiumhexametaphosphate, nitrilotris(methylenephosphonic acid),diethylenetriaminepentaacetic acid, 1-hydroxyethylene, 1,1-diphosphonicacid, and diethylenetriaminepenta-(methylenephosphonic acid). Certaincarboxylic acids, particularly the alpha-hydroxy acids and beta-hydroxyacids, can also function as chelators, e.g., malic acid and tartaricacid. Also included as chelators are compounds highly specific towardferrous or ferric ions such as siderophores, lactoferrin, andtransferrin.

In certain preferred embodiments, the chelating agents useful in thecompositions of the present invention include those selected from thegroup consisting of ethylenediaminetetraacetic acid and salts thereof,succinic acid, and mixtures thereof. Preferably, either the free acid orthe mono- or di-salt form of EDTA is used.

One or more chelating agents may be used in the compositions of thepresent invention at a suitable level to produce the desired result. Ina preferred embodiment, they are present in a total amount of at least0.01 wt-%, more preferably at least 0.05 wt-%, even more preferably atleast 0.1 wt-%, and even more preferably at least 0.25 wt-%, based onthe weight of the ready to use composition. Alternatively, in apreferred embodiment the chelators are present in a total amount of atleast 300 μM (micromolar), preferably at least 500 μM, more preferablyat least 1000 μM and most preferably at least 2000 μM based on the totalweight/volume of composition even if it may comprise multiple phases. Ina preferred embodiment, they are present in a total amount of no greaterthan 10 wt-%, more preferably no greater than 5 wt-%, and even morepreferably no greater than 1 wt-%, based on the weight of the ready touse composition.

The ratio of the total concentration of chelating agents (other thanalpha- or beta-hydroxy acids) to the total concentration of theantiseptic component is preferably within a range of 10:1 to 1:100, andmore preferably 1:1 to 1:10, on a weight basis.

Phenolic Derivative Compounds. A phenolic compound enhancer is typicallya compound having the following general structure:

wherein: m is 0 to 3 (especially 1 to 3), n is 1 to 3 (especially 1 to2), each R¹² independently is alkyl or alkenyl of up to 12 carbon atoms(especially up to 8 carbon atoms) optionally substituted with O in or onthe chain (e.g., as a carbonyl group) or OH on the chain, and each R¹³independently is H or alkyl or alkenyl of up to 8 carbon atoms(especially up to 6 carbon atoms) optionally substituted with O in or onthe chain (e.g., as a carbonyl group) or OH on the chain, but where R¹³is H, n preferably is 1 or 2.

Examples of phenolic derivative enhancers include, but are not limitedto, butylated hydroxy anisole, e.g., 3(2)-tert-butyl-4-methoxyphenol(BHA), 2,6-di-tert-butyl-4-methylphenol (BHT),3,5-di-tert-butyl-4-hydroxybenzylphenol, 2,6-di-tert-4-hexylphenol,2,6-di-tert-4-octylphenol, 2,6-di-tert-4-decylphenol,2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-4-butylphenol,2,5-di-tert-butylphenol, 3,5-di-tert-butylphenol,4,6-di-tert-butyl-resorcinol, methyl paraben (4-hydroxybenzoic acidmethyl ester), ethyl paraben, propyl paraben, butyl paraben,2-phenoxyethanol, as well as combinations thereof A preferred group ofthe phenolic derivative compounds is the phenol species having thegeneral structure shown above where R¹³═H and where R¹² is alkyl oralkenyl of up to 8 carbon atoms, and n is 0, 1, 2, or 3, especiallywhere at least one R¹² is butyl and particularly tert-butyl, andespecially the non-toxic members thereof. Some of the preferred phenolicderivative enhancers are BHA, BHT, methyl paraben, ethyl paraben, propylparaben, and butyl paraben as well as combinations of these.

One or more phenolic derivative compounds may be used in thecompositions of the present invention at a suitable level to produce thedesired result. The concentrations of the phenolic compounds inmedical-grade compositions may vary widely, but as little as 0.001 wt-%,based on the total weight of the composition, can be effective when theabove-described esters are present within the above-noted ranges. In apreferred embodiment, they are present in a total amount of at least0.01 wt-%, more preferably at least 0.10 wt-%, and even more preferablyat least 0.25 wt-%, based on the ready to use composition. In apreferred embodiment, they are present in a total amount of no greaterthan 8 wt-%, more preferably no greater than 4 wt-%, and even morepreferably no greater than 2 wt-%, based on the ready to usecomposition.

It is preferred that the ratio of the total phenolic concentration tothe total concentration of the antiseptic component be within a range of10:1 to 1:300, and more preferably within a range of 1:1 to 1:10, on aweight basis.

The above-noted concentrations of the phenolic derivative enhancers arenormally observed unless concentrated formulations for subsequentdilution are intended. On the other hand, the minimum concentration ofthe phenolics and the antiseptic to provide an antimicrobial effect willvary with the particular application.

Monohydroxy Alcohols. An additional enhancer is a monohydroxy alcoholhaving 1-10 carbon atoms. This includes the lower (i.e., C1-C4)monohydroxy alcohols (e.g., methanol, ethanol, isopropanol, and butanol)as well as longer chain (i.e., C5-C10) monohydroxy alcohols (e.g.,iosbutanol, t-butanol, octanol, and decanol). In certain preferredembodiments, the alcohols useful in the compositions of the presentinvention are selected from the group consisting of methanol, ethanol,isopropyl alcohol, and mixtures thereof.

One or more alcohols may be used in the compositions of the presentinvention at a suitable level to produce the desired result. In a oneembodiment, the short chain (i.e., C1-C4) alcohols are present in atotal amount of at least 5 wt-%, even more preferably at least 10 wt-%,even more preferably at least 15 wt-%, and even more preferably at least20 wt-%, based on the total weight of the ready to use composition. In apreferred embodiment, the (C1-C4)alcohols are present in a total amountof no greater than 50 wt-%, more preferably no greater than 40 wt-%, andeven more preferably no greater than 30 wt-%, based on the total weightof the ready to use composition.

For certain applications, lower alcohols may not be preferred due to thestrong odor and potential for stinging and irritation. This can occurespecially at higher levels. In applications where stinging or burningis a concern, the concentration of (C1-C4)alcohols is preferably lessthan 20%, more preferably less than about 15%.

In a preferred embodiment, longer chain (i.e., C5-C10) alcohols arepresent in a total amount of at least 0.1 wt-%, more preferably at least0.25 wt-%, and even more preferably at least 0.5 wt-%, and mostpreferably at least 1.0%, based on the ready to use composition. In apreferred embodiment, the (C6-C10)alcohols are present in a total amountof no greater than 10 wt-%, more preferably no greater than 5 wt-%, andeven more preferably no greater than 2 wt-%, based on the total weightof the ready to use composition.

Ether glycols. An additional enhancer is an ether glycol. Exemplaryether glycols include those of the formula:R′—O—(CH₂CHR″O)_(n)(CH₂CHR″O)Hwherein R′═H, a (C1-C8)alkyl, or a (C6-C12)aralkyl or alkaryl; and eachR″ is independently=H, methyl, or ethyl; and n=0-5, preferably 1-3.Examples include 2 phenoxyethanol, dipropylene glycol, triethyleneglycol, the line of products available under the trade designationDOWANOL DB (di(ethylene glycol) butyl ether), DOWANOL DPM (di(propyleneglycol)monomethyl ether), and DOWANOL TPnB (tri(propylene glycol)monobutyl ether), as well as many others available from Dow Chemical,Midland Mich.

One or more ether glycols may be used in the compositions of the presentinvention at a suitable level to produce the desired result. In apreferred embodiment, they are present in a total amount of at least0.01 wt-%, based on the total weight of the ready to use composition. Ina preferred embodiment, they are present in a total amount of no greaterthan 20 wt-%, based on the total weight of the ready to use composition.

Surfactants

Compositions of the present invention can include one or moresurfactants to emulsify the composition and to help the composition wetthe surface and/or to aid in contacting the microorganisms. As usedherein the term “surfactant” means an amphiphile (a molecule possessingboth polar and nonpolar regions which are covalently bound) capable ofreducing the surface tension of water and/or the interfacial tensionbetween water and an immiscible liquid. The term is meant to includesoaps, detergents, emulsifiers, surface active agents and the like. Thesurfactant can be cationic, anionic, nonionic, or amphoteric. Thisincludes a wide variety of conventional surfactants; however, certainethoxylated surfactants may reduce or eliminate the antimicrobialefficacy of the antiseptic component. The exact mechanism of this is notknown and not all ethoxylated surfactants display this negative effect.For example, poloxamer (polyethylene oxide/polypropylene oxide)surfactants have been shown to be compatible with some antisepticcomponents, but ethoxylated sorbitan fatty acid esters such as thosesold under the trade name TWEEN by ICI have not been compatible and mayeven be useful in neutralizing the antiseptic in microbiological assays.

Furthermore, certain anionic surfactants may not be compatible with thecationic antiseptics of this invention. It should be noted that theseare broad generalizations and the activity could be formulationdependent. One skilled in the art can easily determine compatibility ofa surfactant by making the formulation and testing for antimicrobialactivity as described in the Examples Section. Combinations of varioussurfactants can be used if desired.

It should be noted that certain antiseptics are amphiphiles and may besurface active. For example, the small molecule quaternary ammoniumcompound antiseptics described herein may be surface active. For thosecompositions that include both an amphiphilic antiseptic and asurfactant, the surfactant is a component separate from the amphiphilicantiseptic.

Preferred surfactants are those that have an HLB (i.e., hydrophile tolipophile balance) of at least 4 and more preferably at least 8. Evenmore preferred surfactants have an HLB of at least 12. Most preferredsurfactants have an HLB of at least 15.

Examples of the various classes of surfactants are described below. Incertain preferred embodiments, the surfactants useful in thecompositions of the present invention are selected from the groupconsisting of sulfonates, sulfates, phosphonates, phosphates, poloxamer(polyethylene oxide/polypropylene oxide block copolymers), cationicsurfactants, and mixtures thereof. Cationic, amphoteric, and non-ionicsurfactants and in particular the ethylene oxide/propylene oxidesurfactants such as poloxamers are particularly preferred for use withcationic antiseptics.

One or more surfactants may be used in the compositions of the presentinvention at a suitable level to produce the desired result. In apreferred embodiment, they are present in a total amount of at least0.01 wt-%, preferably 0.1 wt %, more preferably at least 0.5 wt-%, andeven more preferably at least 1.0 wt-%, based on the total weight of theready to use composition. In a preferred embodiment where, for example,irritation may be a concern, they are present in a total amount of nogreater than 10 wt-%, more preferably no greater than 5 wt-%, and evenmore preferably no greater than 2 wt-%, based on the total weight of theready to use composition. The ratio of the total concentration ofsurfactant to the total concentration of the antiseptic is preferablywithin a range of 5:1 to 1:100, more preferably 3:1 to 1:10, and mostpreferably 2:1 to 1:3, on a weight basis.

Cationic Surfactants. Exemplary cationic surfactants include, but arenot limited to, salts of optionally polyoxyalkylenated primary,secondary, or tertiary fatty amines; quaternary ammonium salts such astetraalkylammonium, alkylamidoalkyltrialkylammonium,trialkylbenzylammonium, trialkylhydroxyalkylammonium, or alkylpyridiniumhaving compatible anionic counterions such as halides (preferablychlorides or bromides) or alkyl sulfates such as methosulfate orethosulfate as well as other anionic counterions; imidazolinederivatives; amine oxides of a cationic nature (e.g., at an acidic pH).

In certain preferred embodiments, the cationic surfactants useful in thecompositions of the present invention are selected from the groupconsisting of tetralkyl ammonium, trialkylbenzylammonium, andalkylpyridinium halides, and mixtures thereof.

Also particularly preferred are amine oxide surfactants including alkyland alkylamidoalkyldialkylamine oxides of the following formula:(R¹⁴)₃—N→Owherein R¹⁴ is a (C1-C30)alkyl group (preferably a (C1-C14)alkyl group)or a (C6-C18)aralklyl or alkaryl group, wherein any of these groups canbe optionally substituted in or on the chain by N—, O—, or S-containinggroups such as amide, ester, hydroxyl, and the like. Each R¹⁴ may be thesame or different provided at least one R¹⁴ group includes at leasteight carbons. Optionally, the R¹⁴ groups can be joined to form aheterocyclic ring with the nitrogen to form surfactants such as amineoxides of alkyl morpholine, alkyl piperazine, and the like. Preferablytwo R¹⁴ groups are methyl and one R¹⁴ group is a (C12-C16)alkyl oralkylamidopropyl group. Examples of amine oxide surfactants includethose commercially available under the trade designations AMMONYX LO,LMDO, and CO, which are lauryldimethylamine oxide,laurylamidopropyldimethylamine oxide, and cetyl amine oxide, all fromStepan Company.

Anionic Surfactants. Exemplary anionic surfactants include, but are notlimited to, sarcosinates, glutamates, alkyl sulfates, sodium orpotassium alkyleth sulfates, ammonium alkyleth sulfates, ammoniumlaureth-n-sulfates, laureth-n-sulfates, isethionates, alkyl and aralkylglycerylether sulfonates, alkyl and aralkyl sulfosuccinates,alkylglyceryl ether sulfonates, alkyl phosphates, aralkyl phosphates,alkylphosphonates, and aralkylphosphonates. These anionic surfactantsmay have a metal or organic ammonium counterion. In certain preferredembodiments, the anionic surfactants useful in the compositions of thepresent invention are selected from the group consisting of:

1. Sulfonates and Sulfates. Suitable anionic surfactants includesulfonates and sulfates such as alkyl sulfates, alkylether sulfates,alkyl sulfonates, alkylether sulfonates, alkylbenzene sufonates,alkylbenzene ether sulfates, alkylsulfoacetates, secondary alkanesulfonates, secondary alkylsulfates, and the like. Many of these can berepresented by the formulas:R¹⁴—(OCH₂CH₂)_(n)(OCH(CH₃)CH₂)_(p)-(Ph)_(a)-(OCH₂CH₂)_(n)—(O)_(b)—SO₃⁻M⁺andR¹⁴—CH[SO₃-M⁺]-R¹⁵wherein: a and b=0 or 1; n, p, and m=0-100 (preferably 0-20, and morepreferably 0-10); R¹⁴ is defined as above provided at least one R¹⁴ orR¹⁵ is at least C8; R¹⁵ is a (C1-C12)alkyl group (saturated straight,branched, or cyclic group) that may be optionally substituted by N, O,or S atoms or hydroxyl, carboxyl, amide, or amine groups; Ph=phenyl; andM is a cationic counterion such as H, Na, K, Li, ammonium, or aprotonated tertiary amine such as triethanolamine or a quaternaryammonium group.

In the formula above, the ethylene oxide groups (i.e., the “n” and “m”groups) and propylene oxide groups (i.e., the “p” groups) can occur inreverse order as well as in a random, sequential, or block arrangement.Preferably for this class, R¹⁴ includes an alkylamide group such asR¹⁶—C(O)N(CH₃)CH₂CH₂— as well as ester groups such as —OC(O)—CH₂—wherein R¹⁶ is a (C8-C22)alkyl group (branched, straight, or cyclicgroup). Examples include, but are not limited to: alkyl ether sulfonatessuch as lauryl ether sulfates such as POLYSTEP B12 (n=3-4, M=sodium) andB22 (n=12, M=ammonium) available from Stepan Company, Northfield, Ill.and sodium methyl taurate (available under the trade designation NIKKOLCMT30 from Nikko Chemicals Co., Tokyo, Japan); secondary alkanesulfonates such as Hostapur SAS which is a Sodium (C14-C17)secondaryalkane sulfonates (alpha-olefin sulfonates) available from ClariantCorp., Charlotte, N.C.; methyl-2-sulfoalkyl esters such as sodiummethyl-2-sulfo(C12-16)ester and disodium 2-sulfo(C12-C16)fatty acidavailable from Stepan Company under the trade designation ALPHASTEPPC-48; alkylsulfoacetates and alkylsulfosuccinates available as sodiumlaurylsulfoacetate (under the trade designation LANTHANOL LAL) anddisodiumlaurethsulfosuccinate (STEPANMILD SL3), both from StepanCompany; alkylsulfates such as ammoniumlauryl sulfate commerciallyavailable under the trade designation STEPANOL AM from Stepan Company;dialkylsulfosuccinates such as dioctylsodiumsulfosuccinate available asAerosol OT from Cytec Industries.

2. Phosphates and Phosphonates. Suitable anionic surfactants alsoinclude phosphates such as alkyl phosphates, alkylether phosphates,aralkylphosphates, and aralkylether phosphates. Many may be representedby the formula:[R¹⁴-(Ph)_(a)-O(CH₂CH₂O)_(n)(CH₂CH(CH₃)O)_(p)]_(q)—P(O)[O⁻M₃₀]_(r)wherein: Ph, R¹⁴, a, n, p, and M are defined above; r is 0-2; and q=1-3;with the proviso that when q=1, r=2, and when q=2, r=1, and when q=3,r=0. As above, the ethylene oxide groups (i.e., the “n” groups) andpropylene oxide groups (i.e., the “p” groups) can occur in reverse orderas well as in a random, sequential, or block arrangement. Examplesinclude a mixture of mono-, di- andtri-(alkyltetraglycolether)-o-phosphoric acid esters generally referredto as trilaureth-4-phosphate commercially available under the tradedesignation HOSTAPHAT 340KL from Clariant Corp., as well as PPG-5 ceteth10 phosphate available under the trade designation CRODAPHOS SG fromCroda Inc., Parsipanny, N.J., and mixtures thereof.

Amphoteric Surfactants. Surfactants of the amphoteric type includesurfactants having tertiary amine groups, which may be protonated, aswell as quaternary amine containing zwitterionic surfactants. Those thathave been particularly useful include:

1. Ammonium Carboxylate Amphoterics. This class of surfactants can berepresented by the following formula:R¹⁷—(C(O)—NH)_(a)—R¹⁸—N⁺(R¹⁹)₂—R²⁰—COO⁻wherein: a=0 or 1; R is a (C7-C21)alkyl group (saturated straight,branched, or cyclic group), a (C6-C22)aryl group, or a (C6-C22)aralkylor alkaryl group (saturated straight, branched, or cyclic alkyl group),wherein R¹⁷ may be optionally substituted with one or more N, O, or Satoms, or one or more hydroxyl, carboxyl, amide, or amine groups; R¹⁹ isH or a (C1-C8)alkyl group (saturated straight, branched, or cyclicgroup), wherein R¹⁹ may be optionally substituted with one or more N, O,or S atoms, or one or more hydroxyl, carboxyl, amine groups, a(C6-C9)aryl group, or a (C6-C9)aralkyl or alkaryl group; and R¹⁸ and R²⁰are each independently a (C1-C10)alkylene group that may be the same ordifferent and may be optionally substituted with one or more N, O, or Satoms, or one or more hydroxyl or amine groups.

More preferably, in the formula above, R¹⁷ is a (C1-C18)alkyl group, R¹⁹is a (C1-C2)alkyl group preferably substituted with a methyl or benzylgroup and most preferably with a methyl group. When R¹⁹ is H it isunderstood that the surfactant at higher pH values could exist as atertiary amine with a cationic counterion such as Na, K, Li, or aquaternary amine group.

Examples of such amphoteric surfactants include, but are not limited to:certain betaines such as cocobetaine and cocamidopropyl betaine(commercially available under the trade designations MACKAM CB-35 andMACKAM L from McIntyre Group Ltd., University Park, Ill.); monoacetatessuch as sodium lauroamphoacetate; diacetates such as disodiumlauroamphoacetate; amino- and alkylamino-propionates such aslauraminopropionic acid (commercially available under the tradedesignations MACKAM 1L, MACKAM 2L, and MACKAM 151 L, respectively, fromMcIntyre Group Ltd.).

2. Ammonium Sulfonate Amphoterics. This class of amphoteric surfactantsare often referred to as “sultaines” or “sulfobetaines” and can berepresented by the following formulaR¹⁷—(C(O)—NH)_(a)—R¹⁸—N⁺(R¹⁹)₂—R²⁰SO3⁻wherein R¹⁷-R²⁰ and “a” are defined above. Examples includecocamidopropylhydroxysultaine (commercially available as MACKAM 50-SBfrom McIntyre Group Ltd.). The sulfoamphoterics may be preferred overthe carboxylate amphoterics since the sulfonate group will remainionized at much lower pH values.

Nonionic Surfactants. Exemplary nonionic surfactants include, but arenot limited to, alkyl glucosides, alkyl polyglucosides, polyhydroxyfatty acid amides, sucrose esters, esters of fatty acids and polyhydricalcohols, fatty acid alkanolamides, ethoxylated fatty acids, ethoxylatedaliphatic acids, ethoxylated fatty alcohols (e.g., octyl phenoxypolyethoxyethanol available under the trade name TRITON X-100 and nonylphenoxy poly(ethyleneoxy) ethanol available under the trade name NONIDETP-40, both from Sigrna, St. Louis, Mo.), ethoxylated and/or propoxylatedaliphatic alcohols (e.g., that available under the trade name Brij fromICI), ethoxylated glycerides, ethoxylated/propoxylated block copolymerssuch as the Pluronic and Tetronic surfactants available from BASF,ethoxylated cyclic ether adducts, ethoxylated amide and imidazolineadducts, ethoxylated amine adducts, ethoxylated mercaptan adducts,ethoxylated condensates with alkyl phenols, ethoxylated nitrogen-basedhydrophobes, ethoxylated polyoxypropylenes, polymeric silicones,fluorinated surfactants (e.g., those available under the trade namesFLUORAD-FS 300 from Minnesota Mining and Manufacturing Co., St. Paul,Minn., and ZONYL from Dupont de Nemours Co., Wilmington, Del.), andpolymerizable (reactive) surfactants (e.g., SAM 211 (alkylene polyalkoxysulfate) surfactant available under the trade name MAZON from PPGIndustries, Inc., Pittsburgh, Pa.). In certain preferred embodiments,the nonionic surfactants useful in the compositions of the presentinvention are selected from the group consisting of Poloxamers such asPLURONIC from BASF, sorbitan fatty acid esters, and mixtures thereof.

Hydrophilic Component

Compositions of the present invention can include a hydrophilic orwater-soluble component to help solubilize and/or physically stabilizethe antiseptic and/or enhancer component in the composition and/or toenhance the antimicrobial efficacy and/or the speed of antimicrobialefficacy. The incorporation of a sufficient amount of hydrophiliccomponent in hydrophobic ointments results in compositions withsignificantly better antimicrobial activity both in terms of speed ofkill and extent of kill. While not intended to be bound by theory it isbelieved that the incorporation of the hydrophilic component allows moreantiseptic to be available at the surface or to more rapidly diffuse tothe surface of the ointment during use. Certain compositions may besolutions, emulsions (one liquid/gel/paste dispersed in anotherliquid/geUpaste), or dispersions (solid in liquid/paste/gel). Ingeneral, for improved antimicrobial activity the ratio of totalhydrophilic component to total hydrophobic component (water insolubleingredients) should be at least 5:95 wt/wt, preferably at least 10:90wt/wt, more preferably at least 15:85 wt/wt and most preferably at least20:80 wt/wt. Levels as high as 30:70, 40:60, 50:50 wt/wt of totalhydrophilic component to total hydrophobic component (water insolubleingredients) or higher may be appropriate for certain compositions.

A hydrophilic material is typically a compound that has a solubility inwater of at least 7 wt-%, preferably at least 10 wt-%, more preferablyat least 20 wt-%, even more preferably at least 25 wt-%, and even morepreferably at least 40 wt-%, at 23° C. Most preferably, a hydrophiliccomponent is infinitely miscible with water at 23° C.

Exemplary hydrophilic components include, but are not limited to, water,polyhydric alcohols, lower alkyl ethers (i.e., having a sufficientlysmall number of carbon atoms to meet the solubility limit above),N-methylpyrrolidone, alkyl esters (i.e., having a sufficiently smallnumber of carbon atoms to meet the solubility limit above), and thelower monohydroxy alcohols discussed above as enhancers, as well ascombinations thereof. Thus, a lower monohydroxy alcohol can function asboth a hydrophilic compound and an enhancer. Preferably, the hydrophiliccomponents include polyhydric alcohols, lower alkyl ethers, and shortchain esters. More preferably, the hydrophilic components includepolyhydric alcohols.

Suitable polyhydric alcohols (i.e., organic compounds having more thanone hydroxyl group) have a molecular weight of less than 500, preferablyless than 400, and more preferably less than 200. Examples of polyhydricalcohols include, but are not limited to, glycerol, propylene glycol,dipropylene glycol, tripropylene glycol, polypropylene glycol,polyethylene glycol, diethylene glycol, pentaerythritol,trimethylolpropane, trimethylolethane, trimethylolbutane, sorbitol,mannitol, xylitol, pantothenol, ethylene glycol adducts of polyhydricalcohol, propylene oxide adducts of polyhydric alcohol, 1,3-butanediol,dipropylene glycol, diglycerine, polyglycerine, erythritol, sorbitan,sugars (e.g., sucrose, glucose, fructose, mannose, xylose, saccharose,trehalose), sugar alcohols, and the like. Certain preferred polyhydricalcohols include glycols (i.e., those containing two hydroxyl groups)including glycerin and propylene glycol. Certain other preferredpolyhydric alcohols include xylitol, mannitol, sorbitol, sucrose andpolyglycerin.

Ethers include materials such as dimethylisosorbide, polyethylene glycoland methoxypolyethylene glycols, block and random copolymers of ethyleneoxide and propylene oxide, and laureth-4. Alkyl esters includetriacetin, methyl acetate, esters of polyethoxylated glycols, andcombinations thereof.

In certain preferred embodiments, the hydrophilic components useful inthe compositions of the present invention include those selected fromthe group consisting of glycols, and in particular glycerin andpropylene glycol, and mixtures thereof.

If there are components in the composition that may esterify withhydroxylfunctional hydrophilic components conditions are selected tominimize this occurrence. For example, the components are not heatedtogether for extended periods of time, the pH is maintained close toneutral if possible, and the like.

One or more hydrophilic materials may be used in the compositions of thepresent invention at a suitable level to produce the desired result. Incertain preferred embodiments that also include a hydrophobic componentas the primary component (i.e., the component used in the greatestamount and referred to as a “vehicle”), the hydrophilic component ispresent in a total amount of at least 0.1%, preferably at least 1 wt-%,more preferably at least 4 wt-%, and even more preferably at least 8wt-%, based on the weight of the ready to use composition In certainembodiments, for example when faster rate of kill is desired, higherlevels of hydrophilic component may be employed. In these cases thehydrophilic component is present in a total amount of at least 10% byweight, more preferably at least 20% by weight and most preferably atleast 25% by weight. In a preferred embodiment, the hydrophiliccomponent is present in a total amount of no greater than 70 wt-%, morepreferably no greater than 60 wt-%, and even more preferably no greaterthan 50 wt-%, based on the ready to use composition. When thehydrophilic component is present in the greatest amount it is referredto as a “vehicle.” When a slower release of the antiseptic is desiredthe hydrophilic component is present in an amount no greater than about30% by weight.

For certain applications it may be desirable to formulate theseantiseptics in compositions comprising a hydrophilic component vehiclethat is thickened with soluble, swellable or insoluble (e.g. insoluble)organic polymeric thickeners or inorganic thickeners such as silica,fumed silica, precipitated silica, silica aerogel and carbon black, andthe like; other particle fillers such as calcium carbonate, magnesiumcarbonate, kaolin, talc, titanium dioxide, aluminum silicate,diatomaceous earth, ferric oxide and zinc oxide, clays, and the like;ceramic microspheres or glass microbubbles; ceramic microspheres suc asthose available under the tradenames “ZEOSPHERES” or “Z-LIGHT” from 3M.The above fillers can be used alone or in combination.

If water is used in certain embodiments, it is present in an amount ofless than 20 wt %, preferably less than 10 wt-%, more preferably lessthan 5 wt-%, and even more preferably less than 2 wt-%, based on theready to use composition. This helps the chemical stability of thecompositions and may reduce irritation. For certain other embodiments,water can be used in a much greater amount, and can even be the primarycomponent, as long as the composition is highly viscous. Preferably,such highly viscous compositions have a viscosity of at least 500centipoise (cps), more preferably at least 1,000 cps, even morepreferably at least 10,000 cps, even more preferably at least 20,000cps, even more preferably at least 50,000 cps, even more preferably atleast 75,000 cps, even more preferably at least 100,000 cps, and evenmore preferably at least 250,000 cps (and even as high as about 500,000cps, 1,000,000 cps, or more). The viscosity can be measured as describedbelow in the Viscosity Test. Most preferred compositions meet theseviscosity values even after heating to 32 C or even 35 C or as high as37 C to ensure when in contact with mammalian tissue the compositionsremain substantive.

Hydrophobic Component

Certain preferred compositions of the present invention also include oneor more hydrophobic materials. A hydrophobic material is typically anorganic compound, which at 23° C. is a liquid, gelatinous, semisolid orsolid and has a solubility in water of less than 5% by weight,preferably less than 1% by weight, more preferably less than 0.5% byweight, and even more preferably less than 0.1% by weight. Thesematerials include compounds typically considered emollients in thecosmetic art.

Examples of general emollients include, but are not limited to, shortchain (i.e, C1-C6) alkyl or (C6-C12)aryl esters of long (i.e., C8-C36)straight or branched chain alkyl or alkenyl alcohols or acids andpolyethoxylated derivatives of the alcohols; short chain (i.e., C1-C6)alkyl or (C6-C12)aryl esters of (C4-C12)diacids or (C4-C12)diolsoptionally substituted in available positions by —OH; (C2-C18)alkyl or(C6-C12)aryl esters of glycerol, pentaerythritol, ethylene glycol,propylene glycol, as well as polyethoxylated derivatives of these;(C12-C22)alkyl esters or (C12-C22)ethers of polypropylene glycol;(C12-C22)alkyl esters or (C12-C22)ethers of polypropyleneglycol/polyethylene glycol copolymer; and polyether polysiloxanecopolymers. Additional examples of hydrophobic components include cyclicdimethicones including volatile cyclic silicones such as D3 and D4,polydialkylsiloxanes, polyaryualkylsiloxanes, silicone copolyols, longchain (i.e., C8-C36) alkyl and alkenyl esters of long (i.e., C8-C18)straight or branched chain alkyl or alkenyl alcohols or acids, longchain (i.e., C8-C36) alkyl and alkenyl amides of long straight orbranched chain (i.e., C8-C36) alkyl or alkenyl amines or acids;hydrocarbons including straight and branched chain alkanes and alkenessuch as isoparafins (e.g. isooctane, isododecane, isooctadecane, etc.),squalene, and mineral oil, polysiloxane polyalkylene copolymers,dialkoxy dimethyl polysiloxanes; (C12-C22)alkyl and (C12-C22)alkenylalcohols, and petroleum derived alkanes such as isoparafins, petrolatum,petrolatum USP, as well as refined natural oils (especially NF or USPgrades) such as olive oil NF, cotton seed oil, peanut oil, corn oil,seasame oil, safflower oil, soybean oil, and the like, and blendsthereof.

In certain preferred embodiments, the hydrophobic components useful inthe compositions of the present invention include those selected fromthe group consisting of petrolatum USP and short chain (i.e., C1-C6)alkyl or (C6-C12)aryl esters of long (i.e., C8-C36) straight or branchedchain alkyl or alkenyl alcohols or acids and polyethoxylated derivativesof the alcohols; short chain (i.e., C1-C6) alkyl or (C6-C12)aryl estersof (C4-C12)diacids or (C4-C12)diols optionally substituted in availablepositions by —OH (such as diisopropyladipate, diisopropylsebacate);(C1-C9)alkyl or (C6-C12)aryl esters of glycerol, pentaerythritol,ethylene glycol, propylene glycol (such as glyceryltricaprylate/caprate); and mixtures thereof. For certain particularlypreferred embodiments, the hydrophobic component is petrolatum.

One or more hydrophobic materials may be used in the compositions of thepresent invention at a suitable level to produce the desired result. Ina preferred embodiment (in which the compositions include very little orno water), the hydrophobic component is present in a total amount of atleast 30 wt-%, preferably at least 50 wt %, more preferably at least 60wt-%, and even more preferably at least 70 wt-%, based on the ready touse composition. In a preferred embodiment, the hydrophobic component ispresent in a total amount of no greater than 99 wt-%, more preferably nogreater than 95 wt-%, and even more preferably no greater than 92 wt-%,based on the ready to use composition. When the hydrophobic component ispresent in the greatest amount it is referred to as a “vehicle.” If thehydrophobic component(s) and the hydrophilic component(s) are present atthe same concentrations the continuous phase is consider the “vehicle”.If the hydrophobic component(s) and the hydrophilic component(s) arepresent at the same concentrations the continuous phase is consider the“vehicle”.

Optional Additives

Compositions of the present invention may additionally employ adjunctcomponents conventionally found in pharmaceutical compositions in theirart-established fashion and at their art-established levels. Thus, forexample, the compositions may contain additional compatiblepharmaceutically active materials for combination therapy (such assupplementary antimicrobials, anti-parasitic agents, antipruritics,astringents, local anaesthetics, steroids, non-steorodialantinflammatory agents, or other anti-inflammatory agents), or maycontain materials useful in physically formulating various dosage formsof the present invention, such as excipients, dyes, perfumes,fragrances, lubricants, thickening agents, stabilizers, skin penetrationenhancers, preservatives, or antioxidants.

It will be appreciated by the skilled artisan that the levels or rangesselected for the required or optional components described herein willdepend upon whether one is formulating a composition for direct use, ora concentrate for dilution prior to use, as well as the specificcomponent selected, the ultimate end-use of the composition, and otherfactors well known to the skilled artisan.

In those applications where emulsions are desirable, an emulsifier maybe used. As used herein, an “emulsifier” means a small molecule orpolymeric amphiphilic compound capable of helping to stabilize anemulsion. Emulsifiers used herein include many of the surfactantsdisclosed but may also include many other amphiphilic molecules. Theemulsions are detectably more stable with the emulsifier present thanwithout as determined by centrifugation and/or freeze thaw studies.

It will also be appreciated that additional antiseptics, disinfectants,or antibiotics may be included and are contemplated. These include, forexample, addition of metals such as silver, copper, zinc; iodine andiodophors: “azole” antifungal agents including clortrimazole,miconazole, econazole, ketoconazole, and salts thereof; and the like.Antibiotics such as neomycin sulfate, bacitracin, mupirocin,tetracycline, polymixin, and the like, also may be included. Preferredcompositions, however, are free of antibiotics due to the chance ofresistance formation.

Formulations and Methods of Preparation

Many of the compositions of the present invention demonstrate a broadspectrum of antimicrobial activity and thus are generally not terminallysterilized but if necessary may be sterilized by a variety of industrystandard techniques. For example, it may be preferred to sterilize thecompositions in their final packaged form using electron beam. It mayalso be possible to sterilize the sample by gamma radiation or heat.Other forms of sterilization may be acceptable. It may also be suitableto include preservatives in the formulation to prevent growth of certainorganisms. Suitable preservatives include industry standard compoundssuch as parabens (methyl, ethyl, propyl, isopropyl, isobutyl, etc), 2bromo-2 nitro-1,3, diol; 5 bromo-5-nitro-1,3 dioxane, chlorbutanol,diazolidinyl urea; iodopropylnyl butylcarbamate, phenoxyethanol,halogenated cresols, methylchloroisothiazolinone and the like, as wellas combinations of these compounds.

The compositions of the present invention preferably adhere well tomammalian tissue (e.g., skin, mucosal tissue, and wounds), in order todeliver the antimicrobial to the intended site over a prolonged periodeven in the presence of perspiration, drainage (e.g., mucosalsecretions), or mild lavage. The compositions are typically non-aqueous,although high viscosity compositions can include a large amount ofwater. The component in the greatest amount (i.e., the vehicle) in theformulations of the invention may be any conventional vehicle commonlyused for topical treatment of human or animal skin. The formulations aretypically selected from one of the following five types: (1)formulations with a hydrophobic vehicle (i.e., the hydrophobiccomponent, which can include one or more hydrophobic compounds, presentin the greatest amount) which may be anhydrous, nearly anhydrous orfurther comprise a aqueous phase; (2) formulations based on water in oilemulsions in which the water insoluble continuous “oil” phase iscomprised of one or more hydrophobic components; (3) formulations with ahydrophilic vehicle (i.e., the hydrophilic component, which can includeone or more hydrophilic compounds, is present in the greatest amount)which may be anhydrous, nearly anhydrous or further comprise a aqueousphase; (4) highly viscous water-based formulations which may besolutions or oil in water emulsions; and (5) neat compositions which areessentially free of a hydrophobic or hydrophilic vehicle componentcomprising antiseptic, optionally an enhancer, and further optionally asurfactant. In this latter case the compositions may optionally bedissolved in a volatile carrier solvent for delivery to the intendedtreatment site or may be delivered to the site as a dry powder, liquid,or semi-solid composition. The different types of compositions arediscussed further below.

(1) Anhydrous or Nearly Anhydrous Formulations with a HydrophobicVehicle: In certain preferred embodiments of the present invention, thecompositions include an antiseptic component in a hydrophobic vehicleoptionally in combination with surfactant(s), an enhancer component, anda small amount of a hydrophilic component. In most instances theenhancers are not soluble in the hydrophobic component at roomtemperature although they may be at elevated temperatures. Thehydrophilic component is generally present in a sufficient amount tostabilize (and perhaps to solubilize) the enhancer(s) in thecomposition. For example, when formulating with organic acid enhancersor certain solid surfactants or certain antiseptics in petrolatum manyantiseptics, enhancers, and surfactants will dissolve into thepetrolatum at temperatures above 85° C.; however, upon cooling, theantiseptic, enhancer and/or surfactant crystals or precipitates back outof solution making it difficult to produce a uniform formulation. If atleast 0.1 wt-%, and preferably at least 1.0 wt-%, more preferably atleast 5 wt %, and most preferably at least 10 wt-% of a hydrophiliccompound (e.g., a glycol) is added a stable formulation can be obtained.It is believed that these formulations produce an emulsion in which theenhancer and/or surfactant is dissolved, emulsified, or dispersed in thehydrophilic component which is emulsified into the hydrophobiccomponent(s). These compositions are stable upon cooling andcentrifuging.

The hydrophilic component also helps to stabilize many of thesurfactants used in preferred formulations. For example,dioctylsulfosuccinate sodium salt (DOSS) dissolves in glycerin atelevated temperatures and helps keep the DOSS physically stable in thecomposition. Furthermore, it is believed that incorporation of thehydrophilic component in the formulation improves the antimicrobialactivity. The mechanism for this is unknown; however, it may speed therelease of the enhancer component and/or the antiseptic component.

The water content of these formulations is preferably less than 20 wt-%,more preferably less than 10 wt-%, and even more preferably less than 5wt-%, and most preferably less than 2 wt-%, in order to minimizechemical degradation of antiseptics present as well as to reduceconcerns with microbial contamination in the composition during storage,and to reduce irritation of the tissue to which it is applied.

These formulations can be manufactured with relative ease. The followingdescription assumes all components are present in order to describetheir manufacture. It is understood, however, that certain compositionsmay not contain one or more of these components. In one method thecompositions are manufactured by first heating the hydrophobic componentto 85° C., adding in the surfactant, hydrophilic component, and optionalenhancer component, cooling to 65° C., and adding the antisepticcomponent which may be above its melting point. Alternatively, theenhancer component, if used, can be predissolved in the hydrophiliccomponent (optionally along with the surfactant) and added to thehydrophobic component either before or after addition of the antisepticcomponent. If either the antiseptic component or the hydrophobiccomponent is solid at room temperature, this is done at the minimumtemperature necessary to ensure dissolution and uniformity of thecomposition. Exposure of ester-containing antiseptics or excipients toenhancers or other components comprising either acid or hydroxyl groupsat elevated temperatures for extended periods of time should be avoidedto prevent transesterification reactions. There are exceptions, forexample, when heating lower purity fatty acid esters in combination withglycol hydrophilic components to produce the monoesters of higherpurity.

Thus, the present invention provides methods of manufacture. One methodinvolves: combining the hydrophobic vehicle and the hydrophiliccomponent with mixing to form a mixture; optionally heating thehydrophobic vehicle to a temperature sufficient to form a pourableliquid (which for many hydrophobic vehicles this is above its meltingpoint) before or after combining it with the hydrophilic component;adding the antiseptic component to the mixture; and cooling the mixturebefore or after adding the antiseptic component.

One preferred method involves: dissolving at least a portion of theenhancer component in the hydrophilic component; combining thehydrophobic vehicle and the hydrophilic component with the enhancercomponent dissolved therein with mixing to form a mixture; optionallyheating the hydrophobic vehicle to a temperature sufficient to form apourable liquid (which for many hydrophobic vehicles this is above itsmelting point) before or after combining it with the hydrophiliccomponent and enhancer component; adding the antiseptic component to themixture; and cooling the mixture before or after adding the antisepticcomponent.

The hydrophilic component may or may not be present in the formulationsthat include a hydrophobic vehicle. Thus, another preferred method ofmanufacture involves: optionally heating the hydrophobic vehicle to atemperature sufficient to form a pourable liquid (which for manyhydrophobic vehicles is above its melting point) before or aftercombining it with the optional enhancer component; adding the antisepticcomponent to the mixture with mixing; and cooling the mixture before orafter adding the antiseptic component.

Surprisingly, it has been found that these compositions aresignificantly less irritating than formulations using hydrophilicvehicles. In blind human trials, participants were asked to instill 0.5gram (g) of ointments based on hydrophobic components (e.g., petrolatum)that include an AHA enhancer, surfactant, and 10 wt-% hydrophiliccomponent (e.g., glycerin) as well as ointments based on hydrophiliccomponents (e.g., PEG 400) using the same enhancer and surfactant. Theointments with the hydrophobic vehicle were preferred by 100% of theparticipants.

The viscosity of these formulations intended for use on skin or in theanterior nares is preferably relatively high to prevent excessivedrainage off the treatment site. Most preferably, the formulationsintended for use on skin, anterior nares, or where drainage would be aconcern are essentially gelatinous at room temperature, having asignificant yield point such that they do not flow readily attemperatures below 35° C. The viscosity is measured using the viscositytest described herein. Certain gelatinous vehicles may also have acharacteristic temperature at which they “melt” or begin to dramaticallylose viscosity. Preferably this is higher than body temperature also toensure that excess drainage of the composition of the treatment sitedoes not occur. Therefore, the melting point of the composition ispreferably greater than 32° C., more preferably greater than 35° C., andeven more preferably greater than about 37° C. The melting point istaken as the lowest temperature at which the viscosity becomesdramatically less or is equal to or less than 100,000 cps.

Alternatively, formulations could be considered which gel or thickenwhen warmed to body temperature. For example, aqueous compositions basedon Pluronic F127 (e.g., greater than about 17% by weight), as well asother Poloxamers of similar structure, are relatively low viscosity at4° C. but when warmed to body temperature become very viscous. In theseapplications, the viscosity should be measured at 35° C.

Similarly the viscosity and/or melt temperature can be enhanced byeither incorporating a crystalline or semicrystalline emulsifier and/orhydrophobic carrier such as a higher melting petrolatum, addition of aninsoluble filler/thixotrope, or by addition of a polymeric thickener(e.g., a polyethylene wax in a petrolatum vehicle). Polymeric thickenersmay be linear, branched, or slightly crosslinked. It is important forcomfort that the formulations are relatively soft and that they spreadeasily to allow easy application, especially over a wound, rash, orinfected area or in the anterior nares. A particularly preferred vehiclefor use on skin, in the anterior nares, or in other areas where highviscosity is desirable is white petrolatum USP having a melting pointgreater than 40° C.

(2) Water in Oil Emulsions: Antiseptic components of this invention canbe formulated into water-in-oil emulsions in combination withenhancer(s) and surfactant(s). Particularly preferred compositionscomprise at least 35 wt-%, preferably at least 40 wt-%, more preferablyat least 45 wt-% and most preferably at least 50% by weight oil phase.As used herein the oil phase is comprised of all components which areeither insoluble in water or preferentially soluble in the oil(s)present at 23)C. One method of preparing these emulsions is described inapplicant's copending U.S. Ser. No. 09/966,571. Generally speaking thehydrophobic component (oil) is mixed in a first container along with anyemulsifier(s) optionally including polymeric emulsifiers and heated to atemperature sufficient to ensure a homogenous composition and subsequentstable emulsion. The temperature is typically raised to at least 60° C.,preferably to at least 80° C. and more preferably to 1 00° C. or more.In a separate second container, the hydrophilic ingredients are mixed,including one or more of the following: water, hydrophilic component,enhancer(s), surfactant(s), and acids/bases to adjust the pH of thefinal composition. The contents of the second container are heated to atemperature sufficient to ensure a stable final emulsion compositionwithout significantly degrading any of the components, typically greaterthan 40° C., preferably greater than 50° C. and more preferably togreater than 60° C. While hot, the second container is added to thefirst container using a high shear mixer. The composition may becontinuously mixed until cool (T<40° C.) or it can be allowed to sit aslong as the contents remain uniformly mixed. If the antiseptic is heatsensitive, it is added with mixing during the cooling down period. If itis not heat sensitive, it may be added to either container. Theviscosity of these compositions may be adjusted by altering the levelsof emulsifier; changing the ratio of water to oil phase; selection ofthe oil phase (e.g., select an oil (hydrophobic component) which is moreor less viscous); incorporation of a polymeric or particulate thickener,etc.

(3) Hydrophilic Vehicle: Antiseptic components of this invention can beformulated into a hydrophilic component such as that based on thehydrophilic compounds discussed above optionally in combination with theenhancer(s) and surfactant(s). Particularly preferred are polyethyleneglycols (PEGs), glycols, and combinations thereof, including blends ofdifferent molecular weight PEGs optionally containing one or moreglycols. When using a hydrophilic component as the vehicle (i.e., thecomponent used in the greatest amount, which can include one or morehydrophilic compounds), it should be preferably selected to maintainviscosity and melt temperature characteristics similar to those statedabove for the anhydrous or nearly anhydrous formulations using ahydrophobic vehicle.

Similarly the viscosity can be enhanced by either incorporating acrystalline or semicrystalline hydrophilic compound such as a PEG ofsufficient molecular weight, addition of an insoluble filler/thixotrope,or by addition of a polymeric thickener. Polymeric thickeners may belinear, branched, or slightly crosslinked. It is important for comfortthat the formulations are relatively soft and that they spread easily toallow easy application, especially in the anterior nares or over awound, rash, or infected area. For this reason, a particularly preferredvehicle is based on a blend of a liquid or semi-solid PEG (PEG 400-1000)with a more crystalline PEG (PEG 1000-2000). Particularly preferred is ablend of PEG 400 with PEG 1450 in a ratio of 4:1.

In certain preferred embodiments of the present invention, thecompositions are in the form of an ointment or cream. That is, thecompositions are in the form of a relatively viscous state such thatthey are suitable for application to nasal passageways.

(4) Water-based Formulations: Aqueous compositions of the presentinvention are those in which water is present in the greatest amount,thereby forming the “vehicle.” For these systems it is particularlyimportant that a relatively high viscosity be imparted to thecomposition to ensure that the antimicrobial composition is not rapidlydispersed off the treated area. These formulations also adhere well totissue and thus deliver the antiseptic to the intended site over aprolonged period even in the presence of perspiration, drainage (e.g.,mucosal secretions), or mild lavage. Such a high viscosity can beimparted by a thickener system. The thickener system of the invention iscompatible with the antiseptic composition described above in order toprovide suitable antimicrobial efficacy, chemical and physicalstability, acceptable cosmetic properties, and appropriate viscosity forretention in the afflicted area.

Preferred thickener systems used in the compositions of the presentinvention are capable of producing viscoelastic compositions that arevery stable. By varying the amount and type of thickener, the degree ofelasticity can be adjusted from almost a purely viscous composition to ahighly elastic and even gel-like composition. If emollients are added,increasing the elasticity and/or yield stress of the system impartsadded stability to prevent separation of immiscible emollients.Excessive elasticity, however, is not preferred because an excessivelyelastic composition usually does not provide a cosmetically appealingproduct.

Significantly, thickener systems used in the present invention arecapable of achieving high viscosities at relatively low totalconcentrations. The total concentration of the thickener system ispreferably less than 8 wt-%, more preferably less than 5 wt-%, and mostpreferably less than 3 wt-%, based on the total weight of the ready touse composition. Preferably, the total concentration of the thickenersystem can be as little as 0.5 wt-%, based on the total weight of thecomposition. For certain embodiments, however, the total concentrationof thickener system is greater than 1 wt-%, based on the total weight ofthe ready to use composition.

The thickener system can include organic polymers or inorganicthixotropes such as silica gel, clays (such as betonite, laponite,hectorite, montmorrillonite and the like), as well as organicallymodified inorganic particulates materials, and the like. As used herein,an organic polymer is considered part of the thickener system if itspresence in the composition results in an increase in the viscosity ofthe composition. Certain polymers that do not have these characteristicsmay also be present in the composition but do not contributesignificantly to the viscosity of the composition. For purposes of thisinvention, they are not considered part of the thickener system. Forexample, certain nonionic polymers such as lower molecular weightpolyethylene glycols (e.g., those having a molecular weight of less than20,000) do not increase the viscosity of the composition significantly.These are considered part of the hydrophilic component, for example,rather than part of the thickener system.

The thickener system can be prepared from one or more nonionic,cationic, anionic, zwitterionic, or associative polymers as long as theyare compatible with the antiseptic and enhancer components of thecomposition. For example, certain acidic enhancers such as those thatinclude carboxylic acid groups are most effective in their protonatedform. This requires that the composition has an acidic pH. For thisreason, many anionic thickeners based on neutralized carboxylic acidgroups would not be suitable. For example, Carbopol-type thickenersbased on polyacrylic acid salts do not typically thicken well at pHvalues of less than 5 and certainly less than a pH of 4.5. Therefore, atlower pH values (i.e., when acidic enhancers are present) if the aqueouscompositions are thickened with anionic polymers, the polymers arepreferably based on sulfonic acid, sulfate, phosphonic acid, orphosphate groups. These polymers are able to thicken at much lower pHvalues due to the lower pKa of these acid groups. Preferred polymers ofthis class include ARISTOFLEX HMB (ammoniumacryloyldimethyltaurate/beheneth-25 methacrylate crosspolymer) andARISTOFLEX ASV (ammonium acryloyldimethyltaurate/NVP copolymer) fromClariant Corporation. Other preferred sulfonic acid polymers are thosedescribed in U.S. Pat. No. 5,318,955.

Preferably, the compositions that include an acidic enhancer componentare thickened using cationic or nonionic thickeners since these performwell at low pH. In addition, many of the nonionic and cationic polymerscan tolerate higher levels of salts and other additives and stillmaintain high viscosity.

A preferred group of nonionic polymeric thickeners include modifiedcelluloses, guar, xanthan gum, and other natural polymers such aspolysaccharides and proteins, associative polymers based on nonionicethylenically unsaturated monomers wherein at least one comonomer has atleast 16 carbon atoms, and polymers based on ethylenically unsaturatedmonomers selected from the group consisting of acrylates, acrylamides,vinyl lactams, vinyl acetate and its hydrolyzed derivatives, methylvinyl ethers, styrene, and acrylonitrile.

A preferred group of cationic polymeric thickeners include cationicallymodified celluloses, quaternized natural amino-functional polymers, andpolymers based on ethylenically unsaturated monomers selected from thegroup consisting of acrylates, acrylamides, vinyl lactams, vinylacetates, methyl vinyl ethers, styrene, and acrylonitrile.

Cationic polymers for use in the compositions of this invention can beselected from both permanently charged quaternary polymers (thosepolymers with quaternary amines such as Polyquaternium 4, 10, 24, 32,and 37, described below) as well as protonated primary, secondary, andtertiary amine functional polymers that have been protonated with asuitable protonic acid. Preferred protonated cationic polymers are basedon tertiary amines. The protonated cationic polymers are preferablyprotonated with suitable acids that will not result in undue skinirritation. These include, for example, (C1-C10)alkylcarboxylic acidsoptionally substituted by oxygen (e.g., acetic acid, alpha-hydroxy acidssuch as lactic acid, gluconic acid, benzoic acid, mandelic acid, and thelike), (C1-C10)alkylsulfonic acids (e.g., methylsulfonic acid andethylsulfonic acid), (C1-C10)alkylhydrogensulfates (e.g.,methylhydrogensulfate) and mineral acids (e.g., hydrochloric acid,hydrobromic acid, sulfuric acid, phosphoric acid, and the like).

The charge on protonated cationic polymers is pH dependent. For thisreason, in order to ensure the polymer is sufficiently protonated, thepH is adjusted appropriately and should be in the range of preferably2-9.5, more preferably 2-8, and most preferably 2.5-7.5. The pH ofpreferred compositions that include acidic enhancers should be lower andis typically 2-5, and preferably 2-4. It should be noted that it is notnecessary to have all of the amines on a particular polymer protonated.The level of protonation will to a certain extent be pH dependent. Withcertain polymers in order to obtain optimum thickening with low skinirritation it may be beneficial to only protonate a small percentage ofthe available amine groups while with other polymers it may bebeneficial to protonate substantially all of the amine groups. This canbe easily determined by one skilled in the art.

The quaternary, tertiary, secondary, and primary amine functionalpolymers may be chosen from natural polymers, modified natural polymers,as well as synthetic polymers. These polymers may be soluble orswellable in the aqueous solvent. Furthermore, these polymers may alsopossess hydrophobic side chains and thus be associative polymers.

Polymers can be classified as soluble, swellable, or associative in theaqueous compositions. Some polymers may fall into one or more of theseclasses. For example, certain associative polymers can be soluble in theaqueous system. Whether they are considered soluble, swellable, orassociative in the aqueous system, suitable polymers for use in thecompositions of the present invention may be film forming or not. Filmforming polymers may retain the active antimicrobial component at theafflicted site for longer periods of time. This may be desirable forcertain applications. For example, some film forming polymers mayproduce compositions that could not be easily washed off with waterafter being applied and dried.

As used herein, a soluble polymer is one that in dilute solution (i.e.,0.01-0.1 wt-% in the desired aqueous solvent system defined ascontaining water and any other hydrophilic compounds), after heating fora sufficient time to ensure solubilization of any potentially solublecomponents, has no significant observable particles of greater than 1micron in particle size, as determined by light scattering measurementsusing, for example, Malvern Masterisizer E Laser Particle Size Analyzeravailable from Malvern Co., Boston, Mass.

As used herein, a swellable polymer is one that in dilute solution(i.e., 0.01-0.1 wt-% in the desired aqueous solvent system), afterheating for a sufficient time to ensure solubilization of anypotentially soluble components, has a significant (i.e., detectable)number of observable particles of greater than 1 micron in particlesize, as determined by light scattering measurements using, for example,Malvern Masterisizer E Laser Particle Size Analyzer.

As used herein, an associative polymer is one that has greater than 2hydrophobic chains per polymer molecule of greater than 12 andpreferably greater than 16 carbon atoms. Examples of such polymers aredescribed below.

Soluble Polymers—Cationic Natural Polymer Derivatives. Cationic modifiedcellulosic polymers are reported in the literature to be soluble inwater. Such polymers have been found to be useful in the presentinvention. The most preferred modified cellulose products are sold underthe trade names CELQUAT (National Starch and Chemicals Corp.,Bridgewater, N.J.) and UCARE (Amerchol Corporation, Edison, N.J.).CELQUAT is a copolymer of a polyethoxylated cellulose anddimethyldiallyl ammonium chloride and has the Cosmetic, Toiletry andFragrance Association (CTFA) designation Polyquaternium-4.

An alkyl modified quaternary ammonium salt of hydroxyethyl cellulose anda trimethyl ammonium chloride substituted epoxide can also be used. Thepolymer conforms to the CTFA designation Polyquatemium 24 and iscommercially available as QUATRISOFT LM-200 from Amerchol Corp., Edison,N.J.

A particularly suitable type of cationic polysaccharide polymer that canbe used is a cationic guar gum derivative, such as guarhydroxypropyltrimonium chloride (Commercially available fromRhone-Poulenc under the trade designation JAGUAR).

Soluble Polymers—Cationic Synthetic Polymers. Synthetic cationic linearpolymers useful in the present invention are preferably quite high incationic charge density—generally having greater than 10 wt-% cationicmonomer, preferably greater than 25 wt-%, and more preferably greaterthan 50 wt-%. This ensures a good cosmetic feel and may actually improvewater solubility. In general, the polymers useful in the presentinvention have sufficient molecular weight to achieve thickening atgenerally less than 5 wt-% polymer, but not too high that thelotion/cream/ointment feels slimy and stringy. While the composition ofthe polymer will dramatically affect the molecular weight at whichsufficient thickening will occur, the polymers preferably have amolecular weight of at least 250,000 daltons, and more preferably atleast 500,000 daltons. The polymers preferably have a molecular weightof no greater than 3,000,000 daltons, and more preferably no greaterthan 1,000,000 daltons. The homopolymers are preferably prepared frommethacryloyloxyalkyl trialkyl ammonium salt, acryloyloxyalkyl trialkylammonium salt, and/or quatemized dialkylaminoalkylacrylamidine salt.Preferably the polymers are copolymers of at least two monomers selectedfrom the group consisting of trialkylaminoalkyl acrylate andmethacrylate salts, dialkyldiallyl ammonium salts,acrylamidoalkyltrialkyl salts, methacrylamidoalkyltrialkyl salts, andalkyl imidazolinium salts, N-vinyl pyrrolidinone, N-vinyl caprolactam,methyl vinyl ether, acrylates, methacrylates, styrene, acrylonitrile,and combinations thereof. Typically, for the salts the counterions arepreferably F—, Cl—, Br—, and CH₃(CH₂)_(n)SO₄— where n=0 to 4.

A variety of quaternary copolymers of varying quatemization, can besynthesized based on homo or copolymers of amino acrylates with methyl,ethyl, or propyl side chains. These monomers could also be copolymerizedwith other nonionic monomers including quaternary acrylic homopolymers,such as homopolymers of 2-methacryloxyethyl trimethylammonium chlorideand 2-methacryloxyethyl methyl diethyl ammonium bromide; and copolymersof quaternary acrylate monomers with a water-soluble monomers, such asPetrolite Product No. Q-0043, a proprietary copolymer of a linearquatemary acrylate and acrylamide at high molecular weight (4-5 millionMW).

Another useful soluble cationic polymer is poly(N,N-dimethylaminopropyl-N-acrylamidine) (which is quaternized withdiethylsulfate) bound to a block of polyacrylonitrile. This blockcopolymer is available under the trade designation Hypan QT-100 fromLipo Chemicals Inc., Paterson, N.J. It is quite effective at thickeningaqueous systems and has a good cosmetic feel. This polymer as received,however, has an objectionable amine odor. The odor could probably bemasked with the proper fragrance, but is preferably removed prior toformulation (e.g., with a solvent cleaning process) so that theformulation can be supplied without fragrance. Preferred compositionsare free of fragrance and colorants.

Suitable cationic polymers include, for example, copolymers of1-vinyl-2-pyrrolidine and 1-vinyl-3-methyl-imidazolium salt (e.g.,chloride salt), referred to in the industry by the Cosmetic, Toiletry,and Fragrance Association, (CTFA) as Polyquatemium-16. This material iscommercially available from BASF Wyandotte Corp. (Parsippany, N.J., USA)under the LUVIQUAT tradename (e.g., LUVIQUAT FC 370); copolymers of1-vinyl-2-pyrrolidine and dimethylaminoethyl methacrylate, referred toin the industry (CTFA) as Polyquatemium-11. This material is availablecommercially from ICI Corp., Wayne, N.J., under the trade designationGAFQUAT; cationic diallyl quaternary ammonium-containing polymersincluding, for example, dimethyldiallyammonium chloride homopolymer andcopolymers of acrylamide and dimethyldiallylammonium chloride, referredto in the industry (CTFA) as Polyquatemium 6 and Polyquatemium 7,respectively.

Soluble Polvmers-Nonionic. A variety of cellulosic ethers are reportedin the literature to be soluble in water. Materials in this class thatare nonionic and have been shown to be useful include:methylhydroxypropylcellulose, available as BENECEL MP 943 from Aqualon,Wilmington, Del.; hydroxypropylcellulose, available as KLUCEL (LF, GF,MF, HF) from Aqualon; hydroxybutylmethylcellulose (3.5 wt-% hydroxybutyland 30 wt-% methoxyl) from Scientific Polymer Products, Ontario, N.Y.;and hydroxyethylcelluloses, available under the trade designationNATROSOL from Aqualon. Xanthan gum, guar, locust bean gum, and otherpolysaccharides may also be suitable. These polymers may be producedfrom plant sources or can be produced through microbial cell culture.Polyvinyl alcohol (PVA) also may be suitable. For example, PVA made frompolyvinyl acetate, which has been hydrolyzed to about 87%, is highlywater soluble at room temperature. Those with higher percent hydrolysisbecome progressively more crystalline and may need to be heated to getinto solution. Protein thickeners such as gelatin and pectin may also beuseful.

Other Soluble Polymers: Amine oxide polymers such as those described inU.S. Pat. No. 6,123,933 and those commercially available under the tradedesignation DIAFORMER Z-711, Z-712, Z-731, and Z-751 from Clariant Corp.are useful. Additionally, zwitterionic polymers, such as methacryloylethyl betaine/acrylate copolymer that are commercially available underthe trade designation DIAFORMER Z-400 from Clariant Corp. can also beused. Zwitterionic polymers described in U.S. Pat. No. 6,590,051 mayalso be useful.

Carboxylic acid functional polymers including naturally occurringcarboxylic acid functional polymers such as hyaluronic acid andderivatives of natural polymers such as carboxymethylcellulose, alginicacid and other alginate polymers, Fucogel (a polysaccharide consistingof three mono-saccharides, fucose, galactose, and galacturonic acid),hyaluronic acid, and the like, also may be useful. Synthetic polymersmay also be useful, such as those based on carboxylic acid, phosphonicacid, or sulfonic acid functional monomers, including but not limitedto, polymers derived from acrylic acid, methacrylic acid, maleicanhydride, itaconic anhydride, sodium AMPS (the sodium salt of2-acrylamido-2-methylpropane sulfonic acid), sulfopropyl acrylate ormethacrylate, sulphomethylated acrylamide, allyl sulphonate, sodiumvinyl sulphonate, combinations thereof, or other water-soluble forms ofthese or other polymerizable carboxylic or sulphonic acids.

Swellable Polymers. Many swellable polymers, which are slightlycrosslinked, function as viscosifiers in aqueous solvent systems. Ingeneral, these swellable polymers are preferred because they tend to befar less “slimy” going on and once the hands perspire and are exposed towater after treatment. Excessive crosslinking will result in polymersthat do not swell sufficiently to increase the viscosity of thecomposition. In order to ensure adequate swelling, if a chemicalcrosslinker is used, the concentration of crosslinker is quite low,e.g., less than about 1000 parts per million (ppm), and preferably lessthan 500 ppm, based on the weight of the dry polymer.

A class of crosslinked polymers suitable for use in the compositions ofthe present invention include acrylamide and at least one otherquaternary monomer selected from the group consisting oftrialkylaminoalkylacrylate and methacrylate salts, dialkyldiallylammonium salts, acrylamidoalkyltrialkyl ammonium salts,methacrylamidoalkyltrialkyl ammonium salts, and monomers that includeimidazolinium salts. The counterions are preferably F—, Cl—, Br—, andCH₃(CH₂)_(n)SO₄— where n=0-4. Other comonomers may also be addedincluding N-vinyl pyrrolidone, N-vinyl caprolactam, methyl vinyl ether,acrylates, methacrylates, styrene, and the like. A particularlypreferred polymer is a poly(2-methacryloxyethyl trimethyl ammoniumchloride) polydimethylaminoethyl methacrylate, which conforms to theCTFA designation Polyquaternium 37. Another preferred polymer includesacrylamide and methacryloyloxyethyl trimethyl ammonium chloride, whichconforms to the CTFA designation Polyquatemium 32. These arecommercially available from Allied Colloids Inc. of Suffolk, Va. asSALCARE SC95, SC96, and SC92.

Other swellable polymers (i.e., slightly crosslinked polymers) can beprepared using ionizing radiation to crosslink. For example, polymers ofN-vinyl lactams, such as N-vinyl pyrrolidone, when exposed to gammaradiation increase in molecular weight and may actually crosslink. Thiscrosslinking allows for more efficient thickening (less polymer requiredto achieve a certain viscosity) and an improved cosmetic feel. Otherpolymers that when exposed to gamma radiation result in crosslinking,include polymers such as LUVIQUAT HM 552 (copolymers of vinylimidazoliummethochloride and vinylpyrrolidone, which conforms to the CTFAdesignation Polyquaternium-16), and GAFQUAT HS-100(vinylpyrrolidone/methacrylamidopropyltrimethylammonium chloridecopolymer which conforms to the CTFA designation Polyquaternium-28).

Chemical crosslinking using polyunsaturated monomers such as diallylmaleate may also prove useful. Other suitable crosslinkers aremulti-ethylenically unsaturated compounds wherein the ethylenic groupsare vinyl groups (including substituted vinyl groups, such asisopropenyl groups), allyl groups, and/or methallyl groups, which groupsare bonded to nitrogen or oxygen atoms. Vinyl, allyl, and methallylgroups, as used herein, include substituted derivatives. Exemplarycompounds include divinyl, diallyl, or dimethallyl esters, ethers,amides, or ureas. Specific examples are disclosed in U.S. Pat. No.5,225,473 (Duan) and U.S. Pat. No. 4,931,282 (Asmus et al.).

A range of crosslinked polyvinylpyrrolidone (PVP) materials has beenprepared via covalent crosslinking with diallyl maleate or by radiationcrosslinking of linear PVP powders. Crosslinked PVP prepared under thesetechniques can produce colloidal particles which are highly swellable inaqueous solutions and thereby produce viscous solutions. The polymersare also nonionic and have excellent compatibility with cationicexcipients.

Anionic swellable polymeric thickeners may also be useful. As describedabove preferred anionic polymers for use with antimicrobial compositionswhich include carboxylic acid functional enhancers (and are thusformulated at lower pH) are polymers having sulfonic acid, sulfonate,phosphonic acid, or phosphate groups.

Associative Polymers. Associative polymers can be used to thicken thecompositions of the present invention as well. Such polymers thicken asa result of hydrophobic or Van de Waals association of hydrophobic sidechains. Such associative polymers can form viscous to gelled aqueoussolutions despite their relatively low molecular weights. Polymers thatare alcoholic soluble can be modified by the addition of a long chainhydrophobic group. A preferred class of such associative polymers isbased on nonionic ethylenically unsaturated monomers wherein at leastone comonomer has at least 12 and preferably at least 16 carbon atoms.

An example is cetyl hydroxyethylcellulose, available as NATROSOL PLUSfrom Aqualon, which utilizes an associative mechanism to enhance theviscosity it produces. Grafted side chains of cetyl alkyl groups canassociate with neighboring alkyl hydrophobes. These interpolymerassociations can dramatically increase the viscosification efficiency ofthe polymer. Longer chain alklyl, alkenyl, and aralkyl groups may alsobe suitable. For example, another preferred associative polymer isArsitoflex HMB, which is ammonium acryloyldimethyltaurate/beheneth-25methacrylate crosspolymer and is available from Clariant Corp.

(5) Neat Compositions: The antiseptic compositions of the presentinvention also may be delivered to the treatment site in a neat form orin a volatile solvent that rapidly evaporates to leave behind a neatcomposition. Such compositions may be solid, semi-solid or liquid. Inthe case where the compositions are solid, the antiseptic and/or theenhancer and/or the surfactant may optionally be microencapsulated toeither sustain the delivery or facilitate manufacturing a powder that iseasily delivered. Alternatively, the composition can be micronized intoa fine powder without the addition of other components or it mayoptionally contain fillers and other ingredients that facilitate powdermanufacture. Suitable powders include but are not limited to calciumcarbonate, calcium phosphate, various sugars, starches, cellulosederivatives, gelatin, and polymers such as polyethylene glycols.

When hydrophobic antiseptics are used, a method for micronizing ahydrophobic agent may be used wherein the hydrophobic agent is dissolvedin an effective amount of a first solvent that is free of polymer suchas the method described in U.S. Pat. No. 6,746,635. The hydrophobicagent and the solvent form a mixture having a continuous phase. A secondsolvent and then an aqueous solution are introduced into the mixture.The introduction of the aqueous solution causes precipitation of thehydrophobic agent and produces a composition of micronized hydrophobicagent having an average particle size of 1 micron or less. The particlesize for use in delivery to the nose or other tissue may besignificantly larger to direct delivery to the proper site. For example,to deliver the antiseptic powder to the nose, nasal cavities, and/orthroat without passing into the lungs, larger particles may be required.

Bioadhesive polymers optionally may be added to the neat compositions aswell as the other physical forms. Numerous suitable bioadhesive polymersare discussed in WO 93/21906. Representative bioadhesive polymers ofparticular interest include bioerodible hydrogels described by H. S.Sawhney, C. P. Pathak and J. A. Hubell in Macromolecules, 1993,26:581-587, polyhyaluronic acids, casein, gelatin, glutin,polyanhydrides, polyacrylic acid, alginate, chitosan, poly(methylmethacrylates), poly(ethyl methacrylates), poly butylmethacrylate),poly(isobutylmethacrylate), poly(hexlmethacrylate), poly(isodeclmethacrylate), poly(lauryl methacrylate), poly(phenyl methacrylate),poly(methyl acrylate), poly(isopropyl acrylate), poly(isobutylacrylate), and poly(octadecl acrylate). Preferred polymers arepolyacrylic acid (e.g. Carbomer) and is poly(fumaric-co-sebacic)acid.Other bioadhesive and bioerodible polymers are described in U.S. Pat.No. 6,746,635. Particularly preferred are slightly crosslinkedpolyacrylic acids such as those sold under the CARBOPOL brand by BFGoodrich.

The antimicrobial compositions also may comprise suitable solid or gelphase carriers or excipients. Examples of such carriers or excipientsinclude but are not limited to calcium carbonate, calcium phosphate,various sugars, starches, cellulose derivatives, gelatin, and polymerssuch as polyethylene glycols.

The neat antiseptic compositions according to the present invention maybe conveniently delivered in the form of an aerosol spray presentationfrom pressurized packs or a nebulizer, with the use of a suitablepropellant, e.g., dichlorodifluoromethane, trichlorofluoromethane,dichlorotetrafluoroethane, carbon dioxide or other suitable gas. In thecase of a pressurized aerosol the dosage unit may be determined byproviding a valve to deliver a metered amount. Capsules and cartridgesof e.g., gelatin for use in an inhaler or insufflator may be formulatedcontaining a powder mix of the compound and a suitable powder base suchas lactose or starch. Those of skill in the art can readily determinethe various parameters and conditions for producing aerosols withoutresort to undue experimentation. Inhaled medications are preferred insome embodiments because of the direct delivery to the lung. Severaltypes of metered dose inhalers are regularly used for administration byinhalation. These types of devices include metered dose inhalers (MDI),breath-actuated MDI, dry powder inhaler (DPI), spacer/holding chambersin combination with MDI, and nebulizers. Techniques for preparingaerosol delivery systems are well known to those of skill in the art.Generally, such systems should utilize components that will notsignificantly impair the biological properties of the agent (see, forexample, Sciarra and Cutie, “Aerosols,” in Remington's PharmaceuticalSciences, 18th edition, 1990, pp. 1694-1712).

The compounds may also be formulated in rectal or vaginal compositionssuch as suppositories or retention enemas, e.g., containing conventionalsuppository bases such as cocoa butter or other glycerides.

Viscosity

The preferred compositions of the present invention have a viscosity ofat least 500 Centipoise (cps) for ease of application topically. Morepreferably, compositions of the present invention have a viscosity of atleast 1,000 cps, even more preferably at least 10,000 cps, even morepreferably at least 20,000 cps, even more preferably at least 50,000cps, even more preferably at least 75,000 cps, even more preferably atleast 100,000 cps, and even more preferably at least 250,000 cps (andeven as high as about 500,000 cps, 1,000,000 cps, or more). Theviscosity can be measured as described below in the Viscosity Test.Preferred formulations have high viscosity even after application tomammalian tissue at 32-37° C. Because certain optional ingredients, suchas enhancers, hydrophilic compounds, hydrophobic compounds, and thelike, may affect the viscosity (either positively or negatively), themeasured viscosity is that of the final composition.

Lower viscosity compositions can be used, however, in certainapplications, such as for the treatment of middle ear infection andchronic sinusitis. For example, afflictions of the middle ear (e.g.,otitis media or infection of the middle ear) may be treated withcompositions of the present invention having a viscosity lower than 1000cps more readily by administration through the outer ear or through thenose and into the Eustachian tubes. The viscosity is measured by theViscosity Test described herein. Preferred compositions meet the aboveviscosity limitations even when warmed to 32° C. Most preferredcompositions meet the above viscosity limitations even when warmed to35° C.

Delivery Methods and Devices

Antimicrobial compositions of the present invention can be provided to amedical professional in a single composite formulation or in multipleparts. For example, a composition can be provided in two parts (e.g., intwo separate containers or two separate compartments of the samecontainer), one part containing the antiseptic component and one partcontaining the enhancer. Other components of the composition can becombined with either one of the two parts. Alternatively, the othercomponents can be included in a third part.

Topical antimicrobial treatment regimens according to the practice ofthis invention include applying a safe and effective amount of thecompositions described herein directly to the infected or at-risk skin,wound, or mucous membrane; particularly, the nasal nares and passagesthat are particularly susceptible to microbial contamination. The doseand frequency of application will depend on many factors including thecondition to be treated, the concentration of antiseptic and optionalenhancer, the microbe to be killed, etc. Typically, the compositionswill be delivered in dosages of at least 10 mg per cm² of tissue,preferably 20 mg per cm² of tissue, more preferably at least 30 mg percm² of tissue, and most preferably at least 50 mg per cm² of tissue formost applications. Application can be made once, or several (e.g., 2-4)times daily for one or more days. Typically, the composition is applied1 or 2 times/day for 1-7 days. For example, decolonization of theanterior nares may require a dose of 0.25 gram (g) per nares applied 1-3times per day for 1-5 days. Treatment of impetigo may require about 0.5g/15 cm² (33mg/cm²) applied 1-3 times/day for 3-10 days.

Compositions of the present invention can be delivered using a varietyof techniques. Typically, the compositions are delivered to the skinand/or mucosal tissue in a manner that allows them to penetrate into theskin and/or mucosal tissue, as opposed to through the tissue into theblood stream. This concentrates the compositions locally at the site inneed of treatment. This delivery can be accomplished by spraying,dipping, wiping, dropping, pouring, toweling, inhaling, or the like,onto the area to be treated.

In the methods of the present invention, the antiseptic compositions maybe provided as a formulation suitable for delivery to mammalian tissue(e.g., skin and/or mucosal surfaces). Suitable formulations can include,but are not limited to, creams, gels, foams, ointments, lotions, balms,waxes, salves, solutions, suspensions, dispersions, water in oil or oilin water emulsions, microemulsions, pastes, powders, oils, lozenges,boluses, and sprays, and the like.

The compositions may be sprayed from a pressurized container. Thepressure may be supplied by an external means such as squeezing thecontainer, through the use of a mechanical pump, or with the use of apropellant. Suitable propellants include chlorofluorocarbons (CFCs),hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs),hydrofluoroethers (HFEs), perfluorinated alkanes, and (C1-C5) alkanes aswell as nitrous oxide and dimethyl ether.

If delivered as a foam, the composition may be dispensed from anaerating dispenser such as the F2 Finger Pump Foamer available from AirSpray International Pompano Beach, Fla. Alternatively, the foam may begenerated using a suitable propellant such as those described above.

For very high viscosity formulations the composition may be delivered inessentially a solid dosage form by placing the composition in or on thetissue to be treated. For example, a small suppository type deliverycould be placed into the anterior nares for eradication ofstaphylococcus sp.

Various other modes of administration can be used as well known to oneof skill in the art depending on the desired location for contact of theantimicrobial compositions of the present invention. For example,afflictions of the middle ear (e.g., otitis media or infection of themiddle ear) may be treated with compositions of the present invention byadministration through the nose and into the Eustachian tubes or theycan be instilled directly into the middle ear through the tympanicmembrane. The formulations may traverse the tympanic membrane with theaid of a syringe or do so by diffusion. Penetration enhancers may beused to enhance diffusion across the tympanic membrane.

For application to skin or mucosal tissue, for example, the compositionsmay be applied directly to the tissue from a collapsible container suchas a flexible tube, blow/fill/seal container, pouch, capsule, etc. Inthis embodiment, the primary container itself is used to dispense thecomposition directly onto the tissue or it can be used to dispense thecomposition onto a separate applicator. For example, for delivery to thenose or other topical tissue, the composition could be dispenseddirectly from a tube and spread by a number of means including squeezingthe outside of the nose together repeatedly, wiping with the tip of thetube or with a separate device such as a spatula, cotton, rayon, orother natural or synthetic based fiber swab.

Other application devices may also be suitable including applicatorswith foam tips, brushes, and the like. Importantly, the applicator mustbe able to deliver the requisite amount of composition to the tissue.Therefore, in most instances applicator devices such as webs and swabsare coated on the applicator web at greater than 50% by weight of thedry web and preferably in excess of 100% by weight of the dry web (on aswab, this would include the weight only of the web).

The collapsible containers may be made in a number of single layer,laminate, or coextruded constructions. Materials of construction mayinclude polyolefins such as low, medium or high density polyethyleneincluding low and linear low density polyethylene, polypropylene, aswell as copolymers of ethylene and/or propylene with other polar ornon-polar comonomers; polyamides such as nylons, polyesters such aspolyethylene terephalate, polybutyleneterephalate,polyethylenenaphthalate; polyurethanes, polyacrylates, and the like. Insome constructions it may be desirable to include a barrier material toprevent evaporation of one or more components of the formulation.Suitable barrier materials include polyesters (e.g., polyethyleneterephthalate, polyethylene naphthalate and polybutylene terephalate andthe like), fluorinated layers such as polytetrafluoroethylene (PTFE,e.g., TEFLON), polyamides (e.g., nylon), chlorotriflouroethylene(ACLAR), polyvinylidene fluoride, as well as copolymers ofperflourinated monomers with partially fluorinated monomers such ascopolymers of tetraflouroethylene/hexafluoropropylene/vinylidenefluoride (THV Fluorothermoplastic from Dyneon Company),polyvinylchloride, polyvinylidene chloride (PVDC, e.g., SARAN HB),ethylene vinyl alcohol (EVOH), polyolefins (e.g., polyethylene, highdensity polyethylene, polypropylene, and combinations thereof). Orientedand biaxially oriented polymers may be particularly preferred.

Particularly preferred barrier constructions include metallic foilbarriers such as aluminum foil laminates, HDPE, PET, PETG, PEN laminatesof polyester and polyolefin (in particular PET/HDPE or HDPE/PET/HDPE),laminates of PET and EVOH, biaxially oriented nylon, PVDC,Nylon/EVOH/Nylon (OXYSHIELD OUB-R), chlorotrifluoroethylene andlaminates thereof, ceramic layer including silicon oxide (SiO_(x) wherex=0.5-2 and preferably 1-2) coated thermoplastics, and ceramic coatedPET (CERAMIS available from CCL Container/Tube Division, Oak Ridge,N.J.).

An antimicrobial composition may be applied to a mucosal surface withthe use of a delivery device such as cervical caps, diaphragms and solidmatrices such as tampons, cotton sponges, cotton swabs, foam sponges,and suppositories. Accordingly, compositions of the present inventioncan also be incorporated in (e.g., delivered from) cloth, sponges, paperproducts (e.g., paper towels, towelettes, and wipes), tampons, undercastpadding, and dental floss, for example.

In some embodiments, an applicator may be used to place the deviceand/or antimicrobial composition in the proper location, for example, onthe mucosal surface of a vagina, nasal cavity, rectum, or the like.Examples of such applicators include, for example, cardboard or plastictube applicators commonly used for inserting tampons or suppositories.

The compositions of the present invention can be delivered from varioussubstrates for delivery to the tissue. For example, the compositions canbe delivered from a wipe or pad which when contacted to tissue willdeliver at least a portion of the composition to the tissue. Forapplication to nasal cavities the compositions may be provided by anon-woven swab such as a “Q-tip” brand cotton swab, into a foam tipapplicator, and the like. The substrate may be used to deliver thecomposition essentially instantaneously or may be left in contact withthe tissue. For example, a substrate in a tubular form could bedelivered to the anterior nares using a suitable applicator and left inthe anterior nares. The annular nature of the device is designed toallow delivery of the active while allowing the patient to freely breaththrough the nose.

Also, compositions of the present invention can be coated onto medicaldevices that contact skin, mucous membranes, wounds, etc. Examples ofsuch devices include catheters such as urinary tract catheters andvascular access catheters.

Objects and advantages of this invention are further illustrated by thefollowing examples, but the particular materials and amounts thereofrecited in these examples, as well as other conditions and details,should not be construed to unduly limit this invention.

Test Protocols

Killing Microbes on Tissue

Many of the compositions of the present invention are intended to killmicroorganisms on mammalian tissue such as skin and mucosal tissue. Theextent of kill can be determined in the following manner. Subjects areidentified who are naturally colonized with the microorganism ofinterest. This is preferred over methods where the tissue isartificially colonized with non-resident flora. For example, subjectsmay be identified whom are colonized with staphylococcus aureus (SA) inthe anterior nares by swabbing the anterior nares and culturing theswab. This is normally repeated at least one additional time to ensurethe subject is a “chronic carrier”, i.e. one who carries the organismall or most of the time. A swab may also be taken several days prior totreatment to increase the probability that the subject is, in fact, acarrier. The subject is then treated with the indicated composition in adose and at a frequency stated. The anterior nares once again areswabbed to determine if the bacteria has been reduced or eradicated(decolonized). Preferred formulations eradicate the SA in less than 72hours, more preferably in less than 48 hours, and most preferably in 24hours or less. On skin the procedure is similar except that a controlsite distinct from the treatment site may be selected on the treatmentday. In this case, a log reduction may be determined. The procedure onskin is described in Federal Register, 21 CFR Parts 333 and 369,Tentative Final Monograph for Healthcare Antiseptic Drug Products;Proposed Rule, 1994 (scrub cup method). When performing this method onskin the antiseptic compositions are generally allowed to remain incontact with the skin for at least 6 hours under a suitable dressingsuch as Tegaderm (3M Company) to check for antimicrobial activity.Preferred formulations show at least 1 log reduction and preferably atleast 1.5 log reduction in 6 hours on a dry skin site (e.g., theabdomen).

Antimicrobial Efficacy Test

This method tries to mimic the actual use conditions for many topicalantiseptics. In most cases a topical antiseptic is applied to the area,optionally with some rubbing, and allowed to remain in contact and killany microorganisms present in an essentially static state. In thisassay, a composition is spread onto a film to form a uniform coating 10mil (250 μm) thick, a suspension of bacteria are directly inoculatedonto the surface of the composition, after a defined period of time, theinoculated disk is placed in a neutralizing broth, and at least aportion of this is diluted and plated to enumerate the survivingbacterial. It should be noted that just as in the in-vivo condition,this in-vitro method takes into account wetting. In certain compositionsthe bacterial suspension will wet the composition very well and spread.With other compositions the bacterial suspension may remain as discretedroplets. This is expected to simulate in-vivo performance in wettingtissue and bacterial biofilms. Since preferred compositions of thepresent invention are ointments this works very well. For less viscouscompositions a compatible thickening agent should be incorporated toachieve a viscosity of at least 20,000 cps and preferably at least50,000 cps.

For all antiseptics used in this assay an initial experiment wasconducted to confirm that the neutralization broth was effective atneutralizing the antiseptic while not damaging the microorganisms. Ingeneral, to confirm neutralization, 100 μL of inoculum (target organismconcentration of 10-100 CFU/mL) was added to 20 mL (for DE neutralizer)of warmed (36° C.) neutralizer broth, vortexed, and a sample disk withointment was dropped into the broth (time zero, t0) and the tube mixedvigorously. This was done using a vortex for the 20 ml samples and byhand shaking for the 100 mL samples. 1 mL aliquots in duplicate werepour plated at three time points: 1) immediately (<1 minute), 2) at 30minutes, and 3) at 60 minutes post-inoculation (all at roomtemperature). Plating was done using tryptic soy agar (TSA). Plates wereincubated at 36 ° C. for up to 48 hours. Plates were enumerated andCFU/mL calculated. The data was converted to log10 CFU/mL. Both testsamples and a numbers control were run. The numbers control consisted of100 μL of inoculum added to 20 mL PBW (phosphate buffered water) toyield an organism concentration of 10-100 CFU/mL. The PBW was preparedas follows: A stock solution was prepared by dissolving 34 grams ofpotassium dihydrogenphosphate in 500 mL deionized water. This wasadjusted to pH 7.2 using 10N sodium hydroxide and then diluted withdeionized water to make exactly 1 liter. The stock solution was filtersterilized and dispensed into a sterile bottle and refrigerated. The PBWwas prepared by adding 1.25 mL stock solution to 1 liter deionized waterand steam sterilized at 121 ° C. for 25 minutes. The solution was mixedby swirling after sterilization to ensure uniformity. A Toxicity Controlwas also run by adding 100 μL of inoculum to 20 mL neutralizer broth toyield an organism concentration of 10-100 CFU/mL.

Neutralizer Effectiveness: If the log10 CFU/mL of the test sample is notmore than 0.3 log less than the corresponding Numbers Control, theneutralization will be considered effective.

Neutralizer Toxicity: If the Toxicity Control (TC) is not more than 0.3log less than the corresponding Numbers Control sample, the samplingsolution will be considered non-toxic.

Test Organisms for Antimicrobial Efficacy Test

The test organisms for this assay were methicillin resistantStaphylococcus aureus, MRSA (ATCC33953), Staphylococcus epidermidis(ATCC35984) and E. coli (ATCC11229). The initial suspension was preparedby suspending bacterial colonies from overnight growth plates inphosphate-buffered water (PBW). A 0.5 McFarland turbidity standard wasused to obtain a cell density of approximately 1.0×108 CFU/mL.

Test Organisms for Antimicrobial Efficacy Test

The samples for this assay spread at room temperature to a uniformthickness of 10 mil (250 μm) using a laboratory knife coater onto a 100μm thick biaxially oriented clean and 70% isopropanol sanitizedpolyesterterephthalate (PET) film. These coated samples were placed insterile petridishes and sealed with Parafilm to prevent evaporation andpreserve cleanliness. Spread samples containing any volatile solventssuch as water were used within 24 hrs of spreading. Test samples werecut from the same PET coated films using a 70% isopropyl alcohol (IPA)disinfected 23 mm die, as described in the next section. The sampledisks were stored in sterile Petri dishes until testing.

Inoculum Preparatin for Antimicrobial Efficacy Test

The inoculum was serially diluted with phosphate buffered water (PBW)10,000 fold (10⁻⁴ ) to achieve a concentration of 1-5×10⁴ CFU/mL. Theinoculum suspension was enumerated at the beginning and end of the testperiod. The final count was within 0.1 log/mL of the initial count. Eachdisk was inoculated with between 10^(6.5) and 10^(7.5) bacteria.

Neutralizing Broth: The DE broth was Dey Engle broth purchased as asolid and reconstituted according to directions from Difco Laboratoris,Detroit Mich. The DE broth was used for all the antiseptics of thisinvention: chlorhexidine gluconate (CHG), polyhexamethylenebiguanide(PHMB), benzethonium chloride, benzalkonium chloride, Healthshieldsilver zeolite, silver nitrate, phospholipid CDM

Measurement of Antimicrobial Acitivity:

After first confirming neutralization, samples were tested forantimicrobial activity using an in vitro model that attempts to simulatein-use conditions. Using aseptic technique and steam sterilizedmaterials (except for the ointments), 23 mm disks of each formulationwere cut using a 70% IPA-disinfected 23 mm die. Three bacteria weretested: Staphylococcus aureus MRSA (ATCC33953), Staphylococcusepidermidis (ATCC35984) and E. coli (ATCC11229). Each inoculum wasprepared by suspending bacterial colonies from overnight growth platesin phosphate-buffered water (PBW). A 0.5 McFarland turbidity standardwas used to obtain a cell density of approximately 1.0×10⁸ CFU/mL. 50 μLof the inoculum was rapidly spotted on the surface of the test ointment(in 8-12 tiny droplets). After the last drop was applied the bacteriawere allowed to remain in contact with the ointment for the specifiedperiod of time (e.g. 2.5 and 10 minutes). At the end of the exposuretime (time bacteria are in contact with the composition) the inoculateddisk was dropped into warm (36° C.) Neutralizer Broth (20 mL for DE) andmixed vigorously (vortexed using a VWR Vortex Genie 2 for 2 minutes).Two one-hundred fold dilutions were prepared in Neutralizer Broth, andthe bacteria enumerated using the pour plate. Plates were incubated at36° C. for up to 48 hours. Colony Forming Units (CFUs) were counted.

The CFUs for each plates were multiplied by the dilution factor toarrive at CFU/mL, and converted to log10 CFU/sample. Log10 CFU/sample ofduplicate tests were averaged and the log10 reduction was calculated.Log reductions were calculated by subtracting the log10 bacterialrecovery of the test materials from the log10 bacterial recovery of thecontrol (100 SL of inoculum in 20 mL warm D/E neutralizing).

Most of the compositions of the present invention were analyzed fortheir ability to kill MRSA and E.coli at 2.5 and 10 minutes. Selectcompositions were analyzed for their ability to kill Staph Epi at 10minutes. By comparison Bactroban Nasal ointment in this assay showedessentially no kill of this strain of MRSA at 2.5 minutes. (The logreduction values were 0.030 and -0.040.) In fact, Bactroban Nasal showedessentially no kill after contact for 2 hours. It is a significantadvantage that the compositions of the present invention are able tokill microorganisms rapidly. Preferred compositions achieve a at least a1.5 log reduction in 10 minutes, more preferably at least a 2 logreduction in 10 minutes, and most preferably at least a 3 log reductionin 10 minutes. Particularly preferred compositions of the presentinvention achieve at least a 1.5 log reduction in 2.5 minutes, morepreferably at least a 2 log reduction in 2.5 minutes, and mostpreferably at least a 3 log reduction in 2.5 minutes.

Viscosity Test

For selected Examples viscosity was measured at approximately 22° C. atambient pressure using a Brookfield LVDV-I⁺ viscometer equipped with amodel D Brookfield heliopath and LV spindles. The spindle and speed waschosen for each particular sample such that the viscometer was operatingin the middle of its range. All samples were allowed to equilibrate atapproximately 22° C. for 24 hours prior to measurement. Preferably theviscosity is taken at the lowest speed possible while staying within20-80% of the viscometer range and more preferably between 30-70% of therange. In all cases the sample size and container geometry was chosen toensure that there were no wall effects. By “wall effects” it is meantthe viscosity value is not affected by the container and is essentiallyequivalent to the viscosity taken in an infinitely large container. Forthis reason lower viscosity samples required a larger sample size toaccommodate the larger spindles. The viscosity of each sample was takenas the highest relatively stable reading achieved on the first path thespindle traversed using 5 the heliopath adapter.

EXAMPLES

TABLE 1 GLOSSARY of COMPONENTS Acronym Trade name Description SourceAddress AC 540 ethylene-acrylic acid Allied-Signal Morristown, copolymerNJ 2-phenoxyethanol 2-phenoxyethanol Aldrich Milwaukee, WI Emulsifying80/20 IOA/MPEG Prepared as St. Paul, MN polymer GG (25% polymer in IPP)described below* Polymer QQ 40/40/20 Prepared as St. Paul, MNSMA/IOA/M90G described below* (25% polymer in IPP) DOSS Aerosol OT-75docusate sodium American W. Patterson, Cyanmid NJ Arlamol E PPG-15stearyl ether Uniqema Patterson, NJ benzalkonium benzalkonium chlorideAldrich Milwaukee, chloride WI benzethonium benzethonium chlorideAldrich Milwaukee, chloride WI Carbowax 400 Polyethyleneglycol 400DOW/Union Danbury, CT Carbide Carowax 1450 Higher MW PEG, e.g DOW/UnionDanbury, CT 1450 Carbide Centroflex F Lecithin Central Soya Fort Wayne,IN Ceraphyl 494 isocetyl stearate ISP Lombard, IL Cerasynt GMS glycerylstearate ISP Lombard, IL CHG chlorhexidine chlorhexidine MedChem Galena,IL gluconate 18.9% gluconate 18.9% Laboratories PHMB Cosmocil CQ 20%Polyhexamethylene- ICI Americas Wilmington, biguanide DE Crodamol GTCCglyceryltricaprate/ Croda Parsippany, caprylate NJ DIPS Dermol DIPSdiisopropyl sebacate Alzo Sayreville, NJ Dowanol DB diethylene glycolbutyl Aldrich Milwaukee, ether WI EDTA EDTA disodium ethylene diamineAldrich Milwaukee, tetraacetic acid, WI disodium glycerin (glycerol)glycerin (glycerol) Aldrich Milwaukee, WI Healthshield Silver ZeoliteHealthshield W. Hartford, CT Hipure 88 lactic acid (88%) Purac AmericaLincolnshire, IL Incroquat Behenyl cationic emulsifying CrodaParsippany, TMS wax NJ Irgasan DP300 Triclosan Ciba Tarrytown, NY IPPisopropylpalmitate isopropylpalmitate Sigma Aldrich St. Louis, MO Dilutelactic acid Lactic acid (10% in DI diluted from — water) Hipure 88 LurolASY alkyl phosphate George A. Monroe, NC Goulston magnesium sulfateMgSO₄ 7H₂O Aldrich Milwaukee, WI methyl paraben methyl paraben GlennCorp St. Paul, MN Mineral oil Mineral oil USP Paddock Labs Minneapolis,MN PCMX Ottasept parachlorometaxylenol Lonza/Happi Ramsey, NJ MPEGPEG475 Poly(ethyleneglycol) Sigma Aldrich St. Louis, MO Methyl EtherMethacrylate (MW475) M90G M90G Poly(ethyleneglycol) Shin-NakamuraWakayama Methyl Ether Chemicals City, Japan Methacrylate CDMPhospholipid phosphatidyl PG- Uniqema Patterson, NJ CDM dimoniumchloride Pluronic P-65 nonionic difunctional BASF Mount Olive, blockcoplymer NJ Polawax emulsifying wax Croda Parsippany, NJ Ritapro 300emulsifying wax Rita Chemicals Woodstock, IL propyl paraben propylparaben KIC Chemicals Armonk, NY propylene glycol 1,2 propanediol JTBaker Phillipsburg, NJ propylene glycol propylene glycol UniqemaPatterson, NJ monocaprate monocaprate Sensiva SC 50 C8 glycerin etherSchuklke & Mayr Norderstedt, GmbH Germany SMA Rocryl 330 StearylMethacrylate Rohm and Haas Philadelphia, PA Silver Nitrate SilverNitrate Aldrich Milwaukee, WI Snow White White Petrolatum USP PenrecoKarns City, PA VAZO-67 2,2′-azobis(2- Dupont Wilmington,methylbutanenitrile) DE

Emulsifying polymer GG was prepared in the following manner. A mixtureof isooctyl acrylate (IOA, 21.6 parts), and MPEG (5.4 parts) [80/20IOA/MPEG, respectively, weight ratio] was dissolved in ethyl acetate (33parts) that contained VAZO 67 radical initiator (0.081 part). Thesolution was contained in a flint glass bottle that was closed with aTeflon-lined metal cap and maintained at 65° C. for 50 hours. Monomerconversion (determined by percent solids measured by loss on drying at105° C.) was essentially complete at 50 hours. Solvent exchange wasaccomplished by adding isopropyl palmitate (IPP) to the ethyl acetatesolution and stripping the lower boiling ethyl acetate on a ROTOVAPevaporator to obtain a 25 weight percent solution of polymer in IPP.

Polymer QQ was prepared in the following manner. A mixture of SMA (10.8parts), IOA (10.8 parts), and M90G (5.4 parts) [80/20, respectively,weight ratio] was dissolved in ethyl acetate (33 parts) that containedVAZO 67 radical initiator (0.081 part). The solution was contained in aflint glass bottle that was closed with a Teflon-lined metal cap andmaintained at 65° C. for 50 hours. Monomer conversion (determined bypercent solids measured by loss on drying at 105° C.) was essentiallycomplete at 50 hours. Solvent exchange was accomplished by addingisopropyl palmitate (EPP) to the ethyl acetate solution and strippingthe lower boiling ethyl acetate on a ROTOVAP evaporator to obtain a 25weight percent solution of polymer in IPP.

Preparation of Examples

Example compositions were prepared according to the procedures listedbelow. The examples were tested according to the Antimicrobial Efficacytest against both MRSA and E.coli at 2.5 minutes and 10 minutes or StaphEpi at 10 minutes.

Control Examples C1-C2

Control compositions of 250 grams each, containing no antimicrobialagents, were prepared using the components shown in Table 2a for eachexample. Carbowax 1450 PEG was heated in an oven until melted in a firstglass container. In a second glass container Glycerin, Carbowax 400 andAerosol OT-75 DOSS were also heated to 70° C. Contents of the secondcontainer were added to the first container, swirled by hand to mix andreheated to 70° C. The composition was removed from the oven and allowedto cool to at least approximately 40° C., while mixing on a roller.

Examples 1-9

Antimicrobial compositions of 125 grams were prepared using thecomponents shown in Tables 2a -2b. For examples 1-6, the antisepticcomponent: Silver Zeolite, phospholipid CDM, Irgasan DP300, benzethoniumchloride, or benzalkonium chloride was combined with Pluronic P-65 andglycerin in a first glass container and heated to 70° C. in an oven.Carbowax 1450 was heated to melting in a separate container then addedto the first container along with the remaining components, swirled byhand to mix and then reheated to 70° C. in the oven. The composition wasremoved from the oven allowed to cool to approximately 40° C., whilemixing on rollers, then transferred into jars and sealed. Examples 7-8,which contained PHMB, and example 9, which contained CHG, were preparedas described above with the exception that there was no initial heatingrequired and these antiseptics were added after all other componentswere combined.

Examples 1-9 comprised hydrophilic vehicles containing a mixture of PEGcompounds and glycerin. Example 1 and 2 incorporated Phospholipid CDM,an antimicrobial quaternary ammonium compound. The antimicrobialefficacy against both MRSA and E. coli was greater than 3 log at 2.5minutes for Example 1. Example 2 further incorporated EDTA as anenhancer. Despite the anionic nature of this enhancer, it increased theantimicrobial efficacy of this quaternary ammonium compound. Example 2killed 3.9 log MRSA and 7.1 log (complete kill) against E. coli at 2.5minutes. Examples 3 and 6 contained the antimicrobial quaternaryammonium compounds benzethonium chloride and benzalkonium chloriderespectively. These compositions exhibited greater than 2 log killagainst MRSA and E. coli after 2.5 minutes exposure. Example 5 used acombination of a quaternary ammonium compound (benzalkonium chloride)and a phenolic antiseptic (triclosan), both at relatively lowconcentration, and exhibited 3.9 log kill against MRSA and 5.2 log killagainst E. coli after 2.5 minutes exposure. Example 4 used asilver/zeolite complex. The composition did not achieve 2 log killagainst either MRSA or E. coli after a 2.5 minutes exposure possiblybecause the silver is not released rapidly enough. In contrast, Example10 (below), which used silver nitrate, achieved 6.3 log kill againstMRSA and 4.8 log kill against E. coli after a 2.5 min. exposure.Examples 7 and 8 used PHMB at 0.2 and 5% respectively. Thesecompositions achieved complete kill (6.8 log) against MRSA and at least4.8 log kill against E. coli after a 10 min. exposure. Example 9incorporated 1.9% total CHG (18.9% solution x 10.4 w/w%=1.9%) and thiscomposition killed 3.1 log MRSA and 6.1 log E. coli after a 2.5 min.exposure.

Example 10

An antimicrobial composition of 250 grams was prepared using thecomponents shown in Table 2b. Carbowax 1450 was preheated to melting(approximately 65° C.), in an oven, in a glass container. All othercomponents, except silver nitrate, were combined with the Carbowax 1450and swirled by hand to mix. The composition was allowed to cool toapproximately 50° C. and then the silver nitrate was added. The solutionwas allowed to further cool to approximately 40° C., then transferred tostorage jars protected from light.

Examples 11-14

Antimicrobial compositions of 120 grams each were prepared using thecomponents shown in Table 2c for each example. Petrolatum was added to afirst glass container and heated in an oven to approximately 70° C. Allother components were added to a second glass container and also heatedin an oven at approximately 70° C. The mixture of components in thesecond container was then added to the first container and then furthermixed using a high shear rotor/stator Silverson homogenizer on highspeed for 1 minute. Mixing was continued at low speed using a Gastoverhead air mixer with radial flow impeller until just before thecomposition congealed at approximately 40° C. The compositions wereremoved from the mixer, poured into jars, and sealed.

Examples 11-14 were formulated in a hydrophobic vehicle. Example 11incorporated CHG as the antiseptic and glycerin as a hydrophiliccomponent and achieved 4.4 and 7.1 log kill against MRSA and E. colirespectively after a 2.5 min. exposure. Examples 12 and 13 hadPhospholipid CDM as the antiseptic and glycerin as a hydrophiliccomponent. Example 12 further incorporated a surfactant, Pluronic P-65.The antimicrobial efficacy of Example 12 was 4.2 log and 2.9 log killagainst MRSA and E. coli respectively. The antimicrobial efficacy ofExample 13 was 5.7 log and 6.3 log against MRSA and E. colirespectively.

Examples 15-16

Examples 15-16, also shown in Table 2c, were prepared in the same manneras Examples 11-14, above, except the benzalkonium chloride was added tothe Petrolatum prior to heating. Examples 11-16 use petrolatum as thehydrophobic vehicle.

Example 15, which incorporated glycerin as a hydrophilic componentachieved complete kill against both MRSA and E. coli after a 2.5 min.exposure. Example 16 which did not incorporate a hydrophilic componentdid not achieve 2 log kill for either MRSA nor E. coli after a 2.5 minexposure.

Examples C3, C4 and 17-18

Control examples C3-C4, containing no antiseptic and CHG antimicrobialcompositions, examples 17-18, were prepared in amounts of 250 gramsusing the components shown in Table 2d for each example. Petrolatum wasused as a hydrophobic vehicle and added to a first glass container andheated in an oven to approximately 70° C. All other components wereadded to a second glass container and also heated in an oven atapproximately 70° C. The mixture of components in the second containerwas then added to the first container and then further mixed using ahigh shear rotor/stator Silverson homogenizer on high speed for 1minute. Mixing was continued at low speed using a Gast overhead airmixer with radial flow impeller until just before the compositioncongealed at approximately 40° C. The compositions were removed from themixer, poured into jars, and sealed.

Examples 17 and 18 used CHG as the antiseptic component. Note that theCHG was incorporated as a solution in water. Examples C3 and C4 were thevehicle controls. Example 17 had 2.5 log kill and 4.8 log kill againstMRSA and E. coli respectively after 2.5 minutes exposure.

Examples 19-21

Antimicrobial compositions of 120 grams each were prepared using thecomponents shown in Table 2d. Petrolatum was added to a first glasscontainer and heated in an oven to approximately 70° C. All othercomponents except CHG were added to a second glass container and heatedin an oven at approximately 50° C. The contents of the second containerwere added to the first container while hand swirling the container tomix. CHG was then added and the mixture was swirled by hand to mix.

Note that CHG, the antiseptic component, was incorporated as a solutionin water. Several enhancers were evaluated including lactic acid/propylparaben and a Dowanol ether. All three examples achieved at least 2.5log kill against both MRSA and E. coli after a 10-minute exposure.

Examples C5, 22-26

Control example C5, containing no antiseptic and examples ofantimicrobial compositions of 120 grams each were prepared using thecomponents shown in Table 2e. Water, glycerin and Lurol ASY were addedto a glass container and heated in an oven to approximately 70 ° C.Examples 22, 25-26 were pH adjusted with sodium hydroxide toapproximately 4.5. All the remaining components were added to a secondglass container, which was swirled by hand and heated in an oven toapproximately 100° C. The contents of the first container were thenadded to the second container and then mixed using a high shearrotor/stator Silverson homogenizer on high speed for approximately 1-2minutes. Each composition was placed in a steam bath and mixed at lowspeed using a Gast overhead air mixer with radial flow impeller. Forexamples 22-26, CHG was then added, followed by high-speed shear mixingfor approximately 1-2 minutes, again using the Silverson homogenizer.Mixing continued until the composition was less than 40° C., using theGast overhead air mixer.

These examples are water in oil emulsions. Examples 24-26, whichincorporated an anionic phosphate surfactant (Lurol ASY), all achievedat least 3 log kill against one of the test organisms. Examples 25 and26 further incorporated lactic acid and achieved greater than 6 log killagainst Staphylococcus epidermidis.

Examples 27-32

Antimicrobial compositions of 250 grams were prepared using thecomponents shown in Table 2f. A mixture of Polawax, mineral oil,Incroquat Behenyl TMS and Centroflex F were added to a first containerand heated to 70° C. in an oven. Water was heated in to 70° C. in aseparate container. The water was added to the first container andfinally CHG or Cosmocil CQ was also added. Each composition was mixedusing a high shear rotor/stator Silverson homogenizer on high speed for1 minute.

These examples are oil in water emulsions comprising CHG or PHMB asantiseptics. Example 27 which did not incorporate lecithin achieved 6.7and 7 log kill against MRSA and E. coli at 2.5 min. Example 28 (2% totalCHG) incorporated lecithin. The lecithin partially inactivated the CHGdecreasing the efficacy against both MRSA and E. coli significantly.Example 30 (only 0.1% total CHG), despite the low level of CHG was ableto kill 2.5 log E. coli after a 10 min. exposure. Example 31 was verysimilar to Example 30 except that it contained lecithin. The CHG wasclearly-neutralized by the lecithin as indicated by essentially noantimicrobial efficacy and further due to the observation of heavybacterial growth in the sample after standing. The sample was notintentionally inoculated. Example 32 had an elevated level of CHG (0.5%total CHG) but due to the presence of lecithin still had less than 0.5log kill against the test organisms.

Examples 6C, 33

Control example 6C and antimicrobial composition Example 33 wereprepared in quantities of 250 grams, using the components shown in Table2g. Benzethonium chloride (Example 33, only) was combined with Ceraphyl494 in a container and heated in an oven to approximately 80° C.Pluronic P-65 and AC540 were added to the container, which was brieflyswirled by hand and then further heated in an oven to approximately 110°C. The composition was removed from the oven, swirled by hand andallowed to cool without stirring.

Example 33 used Ceraphyl 494 as the hydrophobic vehicle and achievedcomplete kill against MRSA at 2.5 and 10 min. and 4.4 log kill againstE. coli after 10 min. exposure.

Antimicrobial Composition Preparation:

Tables 2a-2g show the weight/weight % concentration of each component ineach example composition as well as the antimicrobial efficacy results.A test result of “NT” indicates “not tested.”

TABLE 2a Example Numbers C1 C2 1 2 3 4 5 6 Component w/w % amount ofcomponents Healthshield — — — — — 3.00 — — Phospholipid CDM — — 3.003.00 — — — 2-phenoxyethanol — — — — 0.50 — — — Irgasan DP300 — — — — — —0.50 — Benzethonium — — — — 0.30 — — — Chloride Benzalkonium — — — — — —0.13 2.50 Chloride Disodium EDTA — — — 0.50 — — — — Carbowax 400 61.7860.96 59.00 58.50 59.00 57.00 58.00 59.00 Carowax 1450 16.75 16.53 16.0016.00 17.20 15.00 17.00 16.00 Glycerin 21.47 21.18 20.00 20.00 20.0020.00 20.00 20.50 Pluronic P-65 — — 2.00 2.00 3.00 5.00 4.40 2.00Aerosol OT-75 — 1.33 — — — — — — Total 100.0 100.0 100.0 100.0 100.0100.0 100.0 100.0 Antimicrobial efficacy results: 2.5 min MRSA test 1−0.8 −0.2 3.2 3.9 2.1 0.0 3.4 6.6 2.5 min MRSA test 2 −0.8 −0.3 3.2 3.82.2 0.1 4.3 5.6 Average −0.8 −0.3 3.2 3.9 2.1 0.0 3.9 6.1 2.5 min E colitest 1 −0.5 0.1, 0.9 3.5 7.1* 4.8 0.5 4.5 5.0 2.5 min E coli test 2 −0.50.1, 0.9 4.3 7.1* 5.0 0.2 5.9 5.4 Average −0.5 0.5** 3.9 7.1* 4.9 0.35.2 5.2  10 min MRSA test 1 NT NT NT NT NT 1.5 NT NT  10 min MRSA test 2NT NT NT NT NT 0.6 NT NT Average — — — — — 1.1 — —  10 min E coli test 1NT NT NT NT NT 0.1 NT NT  10 min E coli test 2 NT NT NT NT NT 0.2 NT NTAverage — — — — — 0.2 — — *Complete Kill. **Average of 2 sets of 2results.

TABLE 2b Example Numbers 7 8 9 10 Component w/w % each components SilverNitrate — — — 0.50 PHMB (Cosmocil CQ 20%) 0.20 5.00 — — CHG 18.5% — —10.42 — Carbowax 400 58.19 57.00 55.34 58.55 Carowax 1450 16.56 15.0015.01 15.41 glycerin 20.06 18.00 19.23 20.54 Pluronic P-65 5.00 5.00 —5.00 Total 100.0 100.0 100.0 100.0 Antimicrobial efficacy results: 2.5min MRSA test 1 1.2 2.1 3.0 5.8 2.5 min MRSA test 2 1.4 1.1 3.1 6.8Average 1.3 1.6 3.1 6.3 2.5 min E coli test 1 2.5 2.5 7.1 3.9 2.5 min Ecoli test 2 2.1 4.1 5.1 5.8 Average 2.3 3.3 6.1 4.8  10 min MRSA test 16.8* 6.8* NT NT  10 min MRSA test 2 6.8* 6.8* NT NT Average 6.8* 6.8* ——  10 min E coli test 1 4.5 4.4 NT NT  10 min E coli test 2 5.1 5.5 NTNT Average 4.8 4.9 — — *Complete Kill.

TABLE 2c Example Numbers 11 12 13 14 15 16 Components w/w % amount ofcomponents Phospholipid — 3.00 3.00 3.00 — — CDM Benzalkonium — — — —2.50 2.50 Chloride CHG 18.5% 11.11 — — — — — glycerin 16.00 25.00 25.00— 25.00 — Snow White 67.90 70.00 72.00 95.00 70.50 95.50 Pluronic P-655.00 2.00 — 2.00 2.00 2.00 Total 100.0 100.0 100.0 100.0 100.0 100.0Antimicrobial efficacy results: 2.5 min MRSA 4.2 4.6 4.8 0.6 6.7* 1.9test 1 2.5 min MRSA 4.5 3.7 6.6 0.8 6.7* 1.7 test 2 Average 4.4 4.2 5.70.7 6.7* 1.8 2.5 min E coli 7.1* 2.5, 2.6 5.7 0.7 6.7* 0.7 test 1 2.5min E coli 7.1* 3.5, 3.0 7.0 0.9 6.7* 1.4 test 2 Average 7.1* 2.9** 6.30.8 6.7* 1.1 No antimicrobial efficacy testing was performed at 10minutes for MRSA or E coli. *Complete kill. **Average of two sets of tworesults.

TABLE 2d Example Numbers C3 C4 17 18 19 20 21 Components w/w % amount ofcomponents CHG 18.5% — — 11.11 10.58 10.58 10.60 10.60 glycerin — 20.0020.00 — 20.00 20.00 20.00 Propylene glycol 20.00 — — — — — — Snow White78.00 78.00 66.89 87.40 67.02 62.40 57.40 Pluronic P-65 2.00 2.00 2.002.00 2.00 2.00 2.00 Hipure 88 (lactic acid — — — — 0.20 88%) propylparaben — — — — 0.20 Dowanol DB — — — — — 5.00 10.00 Total 100.0 100.0100.0 100.0 100.00 100.00 100.00 Antimicrobial efficacy results: 2.5 minMRSA test 1 1.6 −0.1 2.6 NT 2.0 NT NT 2.5 min MRSA test 2 1.8 −0.1 2.4NT 2.5 NT NT Average 1.7 −0.1 2.5 — 2.2 — — 2.5 min E coli test 1 NT−0.1 5.0 NT NT NT NT 2.5 min E coli test 2 NT −0.1 4.5 NT NT NT NTAverage — −0.1 4.8 — — — —  10 min MRSA test 1 NT NT NT 3.6 3.7 3.1 2.3 10 min MRSA test 2 NT NT NT 3.3 3.0 3.0 2.4 Average — — — 3.5 3.3 3.12.3  10 min E coli test 1 NT NT NT NT 3.9 2.9 2.5  10 min E coli test 2NT NT NT NT 2.4 2.9 2.6 Average — — — — 3.2 2.9 2.6

TABLE 2e Example Numbers C5 22 23 24 25 26 Components w/w % amount ofcomponents CHG 18.5% — 10.64 10.64 10.64 15.93 15.92 Crodamol — — — —34.93 34.92 GTCC Emulsifying 14.00 14.00 14.00 14.00 — — polymer GGPolymer QQ — — — — 13.97 13.97 glycerin — — 20.00 20.00 — — AC540 1.501.50 1.50 1.50 1.50 1.50 Arlamol E — — 3.00 3.00 2.99 2.99 Dermol DIPS35.00 35.00 35.00 35.00 — — Lurol ASY — — — 2.00 2.00 2.00 Hipure 88 —1.00 — — — — (lactic acid 88%) Lactic acid — — — — 0.21 0.24 10% inwater Pluronic P-65 — — — — 1.00 1.00 Water 49.50 37.86 15.86 13.8627.48 27.48 Total 100.0 100.0 100.0 100.0 100.0 100.0 Antimicrobialefficacy results: 2.5 min MRSA 0.0 0.0 0.6 1.3 NT NT test 1 2.5 min MRSA−0.2 −0.1 0.6 1.1 NT NT test 2 Average −0.1 0.0 0.6 1.2 — —  10 min MRSA0.3 1.7 0.8 1.7 NT NT test 1  10 min MRSA 0.3 2.1 0.8 1.6 NT NT test 2Average 0.3 1.9 0.8 1.7 — —  10 min E coli 0.2 0.2 1.6 2.4 NT NT test 1 10 min E coli 0.7 0.3 1.6 3.9 NT NT test 2 Average 0.4 0.2 1.6 3.2 — — 10 min Staph NT NT NT NT 5.5 6.8* Epi test 1  10 min Staph NT NT NT NT6.8 6.8* Epi test 2 Average — — — — 6.2 6.8* E coli testing at 2.5minutes was not performed. *Complete Kill

TABLE 2f Example Numbers 27 28 29 30 31 32 Components w/w % amount ofcomponents PHMB — — 10.00 — — — (Cosmocil CQ 20%) CHG 18.5% 11.11 11.11— 0.53 0.50 2.50 Polawax 10.00 10.00 10.00 10.00 10.00 10.00 Incroquat3.00 3.00 3.00 3.00 3.00 3.00 Behenyl TMS Mineral oil 5.00 5.00 5.005.00 5.00 5.00 Centroflex F — 4.00 — — 4.00 4.00 Water 70.89 66.89 72.0081.47 77.50 75.50 Total 100.0 100.0 100.0 100.00 100.0 100.0Antimicrobial efficacy results: 2.5 min MRSA 6.7* 4.1 5.6, 4.2 0.8 0.80.5 test 1 2.5 min MRSA 6.7* 4.3 6.6, 5.3 0.8 0.3 0.1 test 2 Average6.7* 4.2 5.4 0.8 0.5 0.3 2.5 min E coli 7.0* 3.0 5.2 NT NT 0.4 test 12.5 min E coli 7.0* 2.9 5.8 NT * 0.4 test 2 Average 7.0* 2.9 5.5 — — 0.4 10 min MRSA NT NT 6.8 1.3 NT NT test 1  10 min MRSA NT NT 5.2 1.4 NT NTtest 2 Average — — 6.0 1.4 — —  10 min E coli NT NT NT 2.5 NT 0.4 test 1 10 min E coli NT NT NT 2.5 NT 0.2 test 2 Average — — — 2.5 — 0.3*Complete kill. **Bacterial growth after 1 month.

TABLE 2g Example Numbers 6C 33 w/w % amount of Components componentsBenzethonium Chloride — 4.00 AC540 6.00 6.00 Pluronic P-65 2.00 2.00Ceraphyl 494 92.00 88.00 Total 100.0 100.0 Antimicrobial efficacyresults: 2.5 min MRSA test 1 −0.1 6.4* 2.5 min MRSA test 2 −0.1 6.4*Average −0.1 6.4*  10 min MRSA test 1 −0.1 6.4*  10 min MRSA test 2 0.16.4* Average 0.0 6.4*  10 min E coli test 1 0.7 1.9  10 min E coli test2 0.5 6.9 Average 0.6 4.4 E coli testing at 2.5 minutes was notperformed. *Complete KillSubject Acceptability of Placebo—First Panel Evaluation

A panel of 10 normal healthy volunteers of either gender over 18 yearsof age evaluated a component composition without active antiseptic todetermine acceptability 10 and to develop evaluation methodology forfuture evaluations.

The compositions evaluated are shown in Table 3.

TABLE 3 Components (weight percent) Docuate Lactic sodium White PEG AcidGlycerin USP petrolatum PEG 3350 Composition USP USP (50%) USP 400 NF NFW 1.00 10.00 2.00 87.00 0.00 0.00 X 1.00 20.00 2.00 0.00 59.00 18.00Test Procedure

A dose was 0.5 mL of Composition W or X applied using a preloaded 1 mLplastic syringe. The volunteers applied the first dose after viewing ademonstration of the technique. The volunteers applied a second andthird dose during Day 1.

One-half of the volunteers (5) were dosed with Composition W andone-half of the volunteers were dosed with Composition X on Day 1 andgiven a Rhinoscopic Examination of Nares before and after application onDay 1 and after 24 hours on Day 2. On Day 8 those volunteers dosed withComposition W on Day 1 received Composition X and those dosed withComposition X on Day 1 received Composition W. They were given aRhinoscopic Examination of Nares before and after application on Day 8and after 24 hours on Day 9.

Volunteers completed a questionnaire on Day 1 and on Day 9.

Results:

All 10 volunteers successfully completed both periods of the study.Descriptive analysis was provided for each categorical variable in thestudy.

Composition W was preferred by 10/10 of the volunteers. Five of tenvolunteers could not complete all three application of Composition X.They cited stinging, burning and runny noses as primary reasons.Composition X caused more rhinorrhea than Composition W. Volunteersusing Composition X felt they could use the ointment for a shorterperiod of time than with Composition W. Composition W could be felt toremain in the nasal vestibule longer (mean 218 minutes) than CompositionX (mean 145 minutes).

Subject acceptability of Placebo—Second Panel Evaluation

A second panel evaluation was done to determine acceptability ofessentially anhydrous ointments based hydrophobic vehicles containinglactic acid or mandelic acid. The criteria for the panel were the sameas for the first panel. The compositions evaluated are given in Table 4.

TABLE 4 Components (weight percent) Lactic DOSS White Acid Mandelic USPGlycerin petrolatum Composition USP Acid (50%) USP USP Y 1.00 0.00 2.0010.00 87.00 Z 0.00 1.00 2.00 10.00 87.00 (emulsion)

The test procedure was the same as that used for the first panel excepta cotton swab was used to apply the composition rather than a tube.

Results:

Both ointments were acceptable with minimal, if any, side effects. Thepreference for the two ointments was fairly equally divided. Four of tenvolunteers expressed a slight preference for the mandelic acidcomposition, three of ten volunteers expressed a slight preference forthe lactic acid composition, and three of ten volunteers noticed nodifference between the compositions.

Each volunteer applied 0.5 mL of composition; however, approximately 0.1gram was routinely left on the swab. Therefore the dose was about 0.2 mLper nares. The time that the ointments remained in the volunteers' nosesvaried between volunteers, but there were indications that the ointmentremained in place up to 24 hours. Two volunteers reported that theointment appeared to accumulate from application to application.

The feel of the ointment in the nose and smell were the most noticedcharacteristics of both ointments, but the characteristics were all inthe acceptable range.

Viscosity Test Results

The viscosity of select examples are shown in Table 5. These were testedat approximately 22 ° C. (72° F.) in accordance with the Viscosity Test.

TABLE 5 Example No. Viscosity cP × 1000  6 1752  9  53 12  300 13 140014 2500 15  800 16  996 17  150 19  4000* 29  130 30  515 31 1400 C1  60C2  70 *Beyond range.

The complete disclosures of the patents, patent documents, andpublications cited herein are incorporated by reference in theirentirety as if each were individually incorparated. Variousmodifications and alterations to this invention will become apparent tothose skilled in the art without departing from the scope and spirit ofthis invention. It should be understood that this invention is notintended to be unduly limited by the illustrative embodiments andexamples set forth herein and that such examples and embodiments arepresented by way of example only with the scope of the inventionintended to be limited only by the claims set forth herein as follows.

What is claimed is:
 1. A method of killing or inactivatingmicroorganisms on mammalian tissue, the method comprising contacting theaffected area with an antimicrobial composition, the antimicrobialcomposition comprising: an antiseptic selected from the group consistingof biguanides, bisbiguanides, polymeric quaternary ammonium compounds,silver and its complexes, small molecule quaternary ammonium compounds,and combinations thereof; wherein the antiseptic is present in a totalamount of at least 0.25 percent by weight based on the total weight ofthe ready to use composition, and wherein when the antiseptic is abiguanide, the composition has a halide salt concentration less than0.1M; a hydrophilic component, wherein the hydrophilic component ispresent in a total amount of at least 4 wt-%; a surfactant; wherein thesurfactant does not reduce or eliminate the antimicrobial activity ofthe antiseptic component a hydrophobic component; water, which ispresent in the composition in the greatest amount; a thickener selectedfrom the group consisting of, cationic polymers, zwitterionic polymers,associative polymers, swellable polymers, and combinations thereof;wherein the cationic polymers are quaternary polymers and/or protonatedtertiary amine functional polymers; wherein the swellable polymers arequaternary, tertiary, secondary, and/or primary amine functionalpolymers; wherein the swellable polymers are slightly crosslinkedpolymers; and wherein the swellable polymers are those which at 0.01 to0.1 wt-% in an aqueous solvent system, after heating for a sufficienttime to ensure solubilization of any potentially soluble components,have a detectable number of observable particles greater than 1 micronin particle size, as determined by light scattering measurement; andwherein the associative polymers are those which have greater than 2hydrophobic chains per polymer molecule of greater than 12 carbon atoms;an enhancer component present in a total amount of greater than 0.4 wt-%based upon the total weight of the ready to use composition andcomprising an alpha-hydroxyl acid, a beta-hydroxy acid, a chelatingagent, a (C1-C4)alkyl carboxylic acid, a (C6-C12)aryl carboxylic acid, a(C6-C12)aralkyl carboxylic acid, a (C6-C12)alkaryl carboxylic acid, aphenolic compound, a (C1-C10)alkyl alcohol, an ether glycol, orcombinations thereof; and less than 20 wt-% of a (C1-C4)alcohol, ifpresent, and wherein the composition achieves at least 2 log reductionin test bacteria in 10 minutes according to the Antimicrobial EfficacyTest.
 2. The method of claim 1 wherein the mammalian tissue is at leasta portion of the nasal cavity, the anterior nares or the esophagealcavity.
 3. The method of claim 1 wherein the small molecule quaternaryammonium compounds are selected from the group consisting of quaternaryammonium compounds having at least one long chain (C6-C18)alkyl,cetylpyridinium halides and their derivatives, benzethonium chloride andits alkyl substituted derivatives, and octenidine.
 4. The method ofclaim 1 wherein the surfactant comprises a sulfonate surfactant, asulfate surfactant, a phosphonate surfactant, a phosphate surfactant, apoloxamer, a cationic surfactant, or mixtures thereof.
 5. The method ofclaim 1 wherein the hydrophilic component comprises a glycol, a loweralcohol ether, a short chain ester, or combinations thereof, and whereinthe hydrophilic component is soluble in water in an amount of at least20 wt-% at 23° C.
 6. The method of claim 1 wherein the hydrophobiccomponent is an organic compound that is liquid, gelatinous, semisolid,or solid at 23° C. and has a solubility in water of less than 5 wt-% at23° C.
 7. The method of claim 1 wherein the microorganisms comprisebacteria and the antimicrobial composition is used in an amounteffective to kill one or more bacteria.
 8. The method of claim 1 whereinthe microorganisms comprise one or more viruses and the antimicrobialcomposition is used in an amount effective to inactivate one or moreviruses.
 9. The method of claim 1 wherein the microorganisms compriseone or more fungi and the antimicrobial composition is used in an amounteffective to kill one or more fungi.
 10. The method of claim 1 whereinthe antiseptic is a polybiguanide.
 11. The method of claim 10 whereinthe polybiguanide is polyhexamethylene biguanide.
 12. The method ofclaim 1 wherein the mammalian tissue comprises skin or mucosal tissue.13. The method of claim 1 wherein the mammalian tissue is present in themiddle ear, tympanic membrane, and/or Eustachian tube of a subject. 14.The method of claim 1 wherein the mammalian tissue is at least a portionof the respiratory system of a subject.
 15. The method of claim 1wherein the mammalian tissue is present in a wound of a subject.
 16. Themethod of claim 1 wherein the mammalian tissue is present in the nose ofa subject.
 17. The method of claim 1 wherein the antimicrobialcomposition is stable physically or chemically.
 18. The method of claim17 wherein the antimicrobial composition is stable physically andchemically.
 19. The method of claim 1 wherein the surfactant is acationic, amphoteric, or nonionic.
 20. The method of claim 19 whereinthe surfactant is nonionic and is an ethylene oxide/propylene oxidesurfactant.